/// An indicator of the behavior of a given field (for example, that a field
/// is required in requests, or given as output but ignored as input).
/// This **does not** change the behavior in protocol buffers itself; it only
/// denotes the behavior and may affect how API tooling handles the field.
///
/// Note: This enum **may** receive new values in the future.
/// A simple descriptor of a resource type.
///
/// ResourceDescriptor annotates a resource message (either by means of a
/// protobuf annotation or use in the service config), and associates the
/// resource's schema, the resource type, and the pattern of the resource name.
///
/// Example:
///
/// message Topic {
/// // Indicates this message defines a resource schema.
/// // Declares the resource type in the format of {service}/{kind}.
/// // For Kubernetes resources, the format is {api group}/{kind}.
/// option (google.api.resource) = {
/// type: "pubsub.googleapis.com/Topic"
/// name_descriptor: {
/// pattern: "projects/{project}/topics/{topic}"
/// parent_type: "cloudresourcemanager.googleapis.com/Project"
/// parent_name_extractor: "projects/{project}"
/// }
/// };
/// }
///
/// The ResourceDescriptor Yaml config will look like:
///
/// resources:
/// - type: "pubsub.googleapis.com/Topic"
/// name_descriptor:
/// - pattern: "projects/{project}/topics/{topic}"
/// parent_type: "cloudresourcemanager.googleapis.com/Project"
/// parent_name_extractor: "projects/{project}"
///
/// Sometimes, resources have multiple patterns, typically because they can
/// live under multiple parents.
///
/// Example:
///
/// message LogEntry {
/// option (google.api.resource) = {
/// type: "logging.googleapis.com/LogEntry"
/// name_descriptor: {
/// pattern: "projects/{project}/logs/{log}"
/// parent_type: "cloudresourcemanager.googleapis.com/Project"
/// parent_name_extractor: "projects/{project}"
/// }
/// name_descriptor: {
/// pattern: "folders/{folder}/logs/{log}"
/// parent_type: "cloudresourcemanager.googleapis.com/Folder"
/// parent_name_extractor: "folders/{folder}"
/// }
/// name_descriptor: {
/// pattern: "organizations/{organization}/logs/{log}"
/// parent_type: "cloudresourcemanager.googleapis.com/Organization"
/// parent_name_extractor: "organizations/{organization}"
/// }
/// name_descriptor: {
/// pattern: "billingAccounts/{billing_account}/logs/{log}"
/// parent_type: "billing.googleapis.com/BillingAccount"
/// parent_name_extractor: "billingAccounts/{billing_account}"
/// }
/// };
/// }
///
/// The ResourceDescriptor Yaml config will look like:
///
/// resources:
/// - type: 'logging.googleapis.com/LogEntry'
/// name_descriptor:
/// - pattern: "projects/{project}/logs/{log}"
/// parent_type: "cloudresourcemanager.googleapis.com/Project"
/// parent_name_extractor: "projects/{project}"
/// - pattern: "folders/{folder}/logs/{log}"
/// parent_type: "cloudresourcemanager.googleapis.com/Folder"
/// parent_name_extractor: "folders/{folder}"
/// - pattern: "organizations/{organization}/logs/{log}"
/// parent_type: "cloudresourcemanager.googleapis.com/Organization"
/// parent_name_extractor: "organizations/{organization}"
/// - pattern: "billingAccounts/{billing_account}/logs/{log}"
/// parent_type: "billing.googleapis.com/BillingAccount"
/// parent_name_extractor: "billingAccounts/{billing_account}"
///
/// For flexible resources, the resource name doesn't contain parent names, but
/// the resource itself has parents for policy evaluation.
///
/// Example:
///
/// message Shelf {
/// option (google.api.resource) = {
/// type: "library.googleapis.com/Shelf"
/// name_descriptor: {
/// pattern: "shelves/{shelf}"
/// parent_type: "cloudresourcemanager.googleapis.com/Project"
/// }
/// name_descriptor: {
/// pattern: "shelves/{shelf}"
/// parent_type: "cloudresourcemanager.googleapis.com/Folder"
/// }
/// };
/// }
///
/// The ResourceDescriptor Yaml config will look like:
///
/// resources:
/// - type: 'library.googleapis.com/Shelf'
/// name_descriptor:
/// - pattern: "shelves/{shelf}"
/// parent_type: "cloudresourcemanager.googleapis.com/Project"
/// - pattern: "shelves/{shelf}"
/// parent_type: "cloudresourcemanager.googleapis.com/Folder"
/// Nested message and enum types in `ResourceDescriptor`.
/// Defines a proto annotation that describes a string field that refers to
/// an API resource.
/// Defines the HTTP configuration for an API service. It contains a list of
/// \[HttpRule][google.api.HttpRule\], each specifying the mapping of an RPC method
/// to one or more HTTP REST API methods.
/// # gRPC Transcoding
///
/// gRPC Transcoding is a feature for mapping between a gRPC method and one or
/// more HTTP REST endpoints. It allows developers to build a single API service
/// that supports both gRPC APIs and REST APIs. Many systems, including [Google
/// APIs](<https://github.com/googleapis/googleapis>),
/// [Cloud Endpoints](<https://cloud.google.com/endpoints>), [gRPC
/// Gateway](<https://github.com/grpc-ecosystem/grpc-gateway>),
/// and \[Envoy\](<https://github.com/envoyproxy/envoy>) proxy support this feature
/// and use it for large scale production services.
///
/// `HttpRule` defines the schema of the gRPC/REST mapping. The mapping specifies
/// how different portions of the gRPC request message are mapped to the URL
/// path, URL query parameters, and HTTP request body. It also controls how the
/// gRPC response message is mapped to the HTTP response body. `HttpRule` is
/// typically specified as an `google.api.http` annotation on the gRPC method.
///
/// Each mapping specifies a URL path template and an HTTP method. The path
/// template may refer to one or more fields in the gRPC request message, as long
/// as each field is a non-repeated field with a primitive (non-message) type.
/// The path template controls how fields of the request message are mapped to
/// the URL path.
///
/// Example:
///
/// service Messaging {
/// rpc GetMessage(GetMessageRequest) returns (Message) {
/// option (google.api.http) = {
/// get: "/v1/{name=messages/*}"
/// };
/// }
/// }
/// message GetMessageRequest {
/// string name = 1; // Mapped to URL path.
/// }
/// message Message {
/// string text = 1; // The resource content.
/// }
///
/// This enables an HTTP REST to gRPC mapping as below:
///
/// HTTP | gRPC
/// -----|-----
/// `GET /v1/messages/123456` | `GetMessage(name: "messages/123456")`
///
/// Any fields in the request message which are not bound by the path template
/// automatically become HTTP query parameters if there is no HTTP request body.
/// For example:
///
/// service Messaging {
/// rpc GetMessage(GetMessageRequest) returns (Message) {
/// option (google.api.http) = {
/// get:"/v1/messages/{message_id}"
/// };
/// }
/// }
/// message GetMessageRequest {
/// message SubMessage {
/// string subfield = 1;
/// }
/// string message_id = 1; // Mapped to URL path.
/// int64 revision = 2; // Mapped to URL query parameter `revision`.
/// SubMessage sub = 3; // Mapped to URL query parameter `sub.subfield`.
/// }
///
/// This enables a HTTP JSON to RPC mapping as below:
///
/// HTTP | gRPC
/// -----|-----
/// `GET /v1/messages/123456?revision=2&sub.subfield=foo` |
/// `GetMessage(message_id: "123456" revision: 2 sub: SubMessage(subfield:
/// "foo"))`
///
/// Note that fields which are mapped to URL query parameters must have a
/// primitive type or a repeated primitive type or a non-repeated message type.
/// In the case of a repeated type, the parameter can be repeated in the URL
/// as `...?param=A¶m=B`. In the case of a message type, each field of the
/// message is mapped to a separate parameter, such as
/// `...?foo.a=A&foo.b=B&foo.c=C`.
///
/// For HTTP methods that allow a request body, the `body` field
/// specifies the mapping. Consider a REST update method on the
/// message resource collection:
///
/// service Messaging {
/// rpc UpdateMessage(UpdateMessageRequest) returns (Message) {
/// option (google.api.http) = {
/// patch: "/v1/messages/{message_id}"
/// body: "message"
/// };
/// }
/// }
/// message UpdateMessageRequest {
/// string message_id = 1; // mapped to the URL
/// Message message = 2; // mapped to the body
/// }
///
/// The following HTTP JSON to RPC mapping is enabled, where the
/// representation of the JSON in the request body is determined by
/// protos JSON encoding:
///
/// HTTP | gRPC
/// -----|-----
/// `PATCH /v1/messages/123456 { "text": "Hi!" }` | `UpdateMessage(message_id:
/// "123456" message { text: "Hi!" })`
///
/// The special name `*` can be used in the body mapping to define that
/// every field not bound by the path template should be mapped to the
/// request body. This enables the following alternative definition of
/// the update method:
///
/// service Messaging {
/// rpc UpdateMessage(Message) returns (Message) {
/// option (google.api.http) = {
/// patch: "/v1/messages/{message_id}"
/// body: "*"
/// };
/// }
/// }
/// message Message {
/// string message_id = 1;
/// string text = 2;
/// }
///
///
/// The following HTTP JSON to RPC mapping is enabled:
///
/// HTTP | gRPC
/// -----|-----
/// `PATCH /v1/messages/123456 { "text": "Hi!" }` | `UpdateMessage(message_id:
/// "123456" text: "Hi!")`
///
/// Note that when using `*` in the body mapping, it is not possible to
/// have HTTP parameters, as all fields not bound by the path end in
/// the body. This makes this option more rarely used in practice when
/// defining REST APIs. The common usage of `*` is in custom methods
/// which don't use the URL at all for transferring data.
///
/// It is possible to define multiple HTTP methods for one RPC by using
/// the `additional_bindings` option. Example:
///
/// service Messaging {
/// rpc GetMessage(GetMessageRequest) returns (Message) {
/// option (google.api.http) = {
/// get: "/v1/messages/{message_id}"
/// additional_bindings {
/// get: "/v1/users/{user_id}/messages/{message_id}"
/// }
/// };
/// }
/// }
/// message GetMessageRequest {
/// string message_id = 1;
/// string user_id = 2;
/// }
///
/// This enables the following two alternative HTTP JSON to RPC mappings:
///
/// HTTP | gRPC
/// -----|-----
/// `GET /v1/messages/123456` | `GetMessage(message_id: "123456")`
/// `GET /v1/users/me/messages/123456` | `GetMessage(user_id: "me" message_id:
/// "123456")`
///
/// ## Rules for HTTP mapping
///
/// 1. Leaf request fields (recursive expansion nested messages in the request
/// message) are classified into three categories:
/// - Fields referred by the path template. They are passed via the URL path.
/// - Fields referred by the \[HttpRule.body][google.api.HttpRule.body\]. They are passed via the HTTP
/// request body.
/// - All other fields are passed via the URL query parameters, and the
/// parameter name is the field path in the request message. A repeated
/// field can be represented as multiple query parameters under the same
/// name.
/// 2. If \[HttpRule.body][google.api.HttpRule.body\] is "*", there is no URL query parameter, all fields
/// are passed via URL path and HTTP request body.
/// 3. If \[HttpRule.body][google.api.HttpRule.body\] is omitted, there is no HTTP request body, all
/// fields are passed via URL path and URL query parameters.
///
/// ### Path template syntax
///
/// Template = "/" Segments [ Verb ] ;
/// Segments = Segment { "/" Segment } ;
/// Segment = "*" | "**" | LITERAL | Variable ;
/// Variable = "{" FieldPath [ "=" Segments ] "}" ;
/// FieldPath = IDENT { "." IDENT } ;
/// Verb = ":" LITERAL ;
///
/// The syntax `*` matches a single URL path segment. The syntax `**` matches
/// zero or more URL path segments, which must be the last part of the URL path
/// except the `Verb`.
///
/// The syntax `Variable` matches part of the URL path as specified by its
/// template. A variable template must not contain other variables. If a variable
/// matches a single path segment, its template may be omitted, e.g. `{var}`
/// is equivalent to `{var=*}`.
///
/// The syntax `LITERAL` matches literal text in the URL path. If the `LITERAL`
/// contains any reserved character, such characters should be percent-encoded
/// before the matching.
///
/// If a variable contains exactly one path segment, such as `"{var}"` or
/// `"{var=*}"`, when such a variable is expanded into a URL path on the client
/// side, all characters except `\[-_.~0-9a-zA-Z\]` are percent-encoded. The
/// server side does the reverse decoding. Such variables show up in the
/// [Discovery
/// Document](<https://developers.google.com/discovery/v1/reference/apis>) as
/// `{var}`.
///
/// If a variable contains multiple path segments, such as `"{var=foo/*}"`
/// or `"{var=**}"`, when such a variable is expanded into a URL path on the
/// client side, all characters except `\[-_.~/0-9a-zA-Z\]` are percent-encoded.
/// The server side does the reverse decoding, except "%2F" and "%2f" are left
/// unchanged. Such variables show up in the
/// [Discovery
/// Document](<https://developers.google.com/discovery/v1/reference/apis>) as
/// `{+var}`.
///
/// ## Using gRPC API Service Configuration
///
/// gRPC API Service Configuration (service config) is a configuration language
/// for configuring a gRPC service to become a user-facing product. The
/// service config is simply the YAML representation of the `google.api.Service`
/// proto message.
///
/// As an alternative to annotating your proto file, you can configure gRPC
/// transcoding in your service config YAML files. You do this by specifying a
/// `HttpRule` that maps the gRPC method to a REST endpoint, achieving the same
/// effect as the proto annotation. This can be particularly useful if you
/// have a proto that is reused in multiple services. Note that any transcoding
/// specified in the service config will override any matching transcoding
/// configuration in the proto.
///
/// Example:
///
/// http:
/// rules:
/// # Selects a gRPC method and applies HttpRule to it.
/// - selector: example.v1.Messaging.GetMessage
/// get: /v1/messages/{message_id}/{sub.subfield}
///
/// ## Special notes
///
/// When gRPC Transcoding is used to map a gRPC to JSON REST endpoints, the
/// proto to JSON conversion must follow the [proto3
/// specification](<https://developers.google.com/protocol-buffers/docs/proto3#json>).
///
/// While the single segment variable follows the semantics of
/// [RFC 6570](<https://tools.ietf.org/html/rfc6570>) Section 3.2.2 Simple String
/// Expansion, the multi segment variable **does not** follow RFC 6570 Section
/// 3.2.3 Reserved Expansion. The reason is that the Reserved Expansion
/// does not expand special characters like `?` and `#`, which would lead
/// to invalid URLs. As the result, gRPC Transcoding uses a custom encoding
/// for multi segment variables.
///
/// The path variables **must not** refer to any repeated or mapped field,
/// because client libraries are not capable of handling such variable expansion.
///
/// The path variables **must not** capture the leading "/" character. The reason
/// is that the most common use case "{var}" does not capture the leading "/"
/// character. For consistency, all path variables must share the same behavior.
///
/// Repeated message fields must not be mapped to URL query parameters, because
/// no client library can support such complicated mapping.
///
/// If an API needs to use a JSON array for request or response body, it can map
/// the request or response body to a repeated field. However, some gRPC
/// Transcoding implementations may not support this feature.
/// Nested message and enum types in `HttpRule`.
/// A custom pattern is used for defining custom HTTP verb.
/// `Authentication` defines the authentication configuration for API methods
/// provided by an API service.
///
/// Example:
///
/// name: calendar.googleapis.com
/// authentication:
/// providers:
/// - id: google_calendar_auth
/// jwks_uri: <https://www.googleapis.com/oauth2/v1/certs>
/// issuer: <https://securetoken.google.com>
/// rules:
/// - selector: "*"
/// requirements:
/// provider_id: google_calendar_auth
/// - selector: google.calendar.Delegate
/// oauth:
/// canonical_scopes: <https://www.googleapis.com/auth/calendar.read>
/// Authentication rules for the service.
///
/// By default, if a method has any authentication requirements, every request
/// must include a valid credential matching one of the requirements.
/// It's an error to include more than one kind of credential in a single
/// request.
///
/// If a method doesn't have any auth requirements, request credentials will be
/// ignored.
/// Specifies a location to extract JWT from an API request.
/// Nested message and enum types in `JwtLocation`.
/// Configuration for an authentication provider, including support for
/// [JSON Web Token
/// (JWT)](<https://tools.ietf.org/html/draft-ietf-oauth-json-web-token-32>).
/// OAuth scopes are a way to define data and permissions on data. For example,
/// there are scopes defined for "Read-only access to Google Calendar" and
/// "Access to Cloud Platform". Users can consent to a scope for an application,
/// giving it permission to access that data on their behalf.
///
/// OAuth scope specifications should be fairly coarse grained; a user will need
/// to see and understand the text description of what your scope means.
///
/// In most cases: use one or at most two OAuth scopes for an entire family of
/// products. If your product has multiple APIs, you should probably be sharing
/// the OAuth scope across all of those APIs.
///
/// When you need finer grained OAuth consent screens: talk with your product
/// management about how developers will use them in practice.
///
/// Please note that even though each of the canonical scopes is enough for a
/// request to be accepted and passed to the backend, a request can still fail
/// due to the backend requiring additional scopes or permissions.
/// User-defined authentication requirements, including support for
/// [JSON Web Token
/// (JWT)](<https://tools.ietf.org/html/draft-ietf-oauth-json-web-token-32>).
/// `Backend` defines the backend configuration for a service.
/// A backend rule provides configuration for an individual API element.
/// Nested message and enum types in `BackendRule`.
/// A description of a label.
/// Nested message and enum types in `LabelDescriptor`.
/// The launch stage as defined by [Google Cloud Platform
/// Launch Stages](<http://cloud.google.com/terms/launch-stages>).
/// Defines a metric type and its schema. Once a metric descriptor is created,
/// deleting or altering it stops data collection and makes the metric type's
/// existing data unusable.
///
/// Nested message and enum types in `MetricDescriptor`.
/// A specific metric, identified by specifying values for all of the
/// labels of a \[`MetricDescriptor`][google.api.MetricDescriptor\].
/// Billing related configuration of the service.
///
/// The following example shows how to configure monitored resources and metrics
/// for billing, `consumer_destinations` is the only supported destination and
/// the monitored resources need at least one label key
/// `cloud.googleapis.com/location` to indicate the location of the billing
/// usage, using different monitored resources between monitoring and billing is
/// recommended so they can be evolved independently:
///
///
/// monitored_resources:
/// - type: library.googleapis.com/billing_branch
/// labels:
/// - key: cloud.googleapis.com/location
/// description: |
/// Predefined label to support billing location restriction.
/// - key: city
/// description: |
/// Custom label to define the city where the library branch is located
/// in.
/// - key: name
/// description: Custom label to define the name of the library branch.
/// metrics:
/// - name: library.googleapis.com/book/borrowed_count
/// metric_kind: DELTA
/// value_type: INT64
/// unit: "1"
/// billing:
/// consumer_destinations:
/// - monitored_resource: library.googleapis.com/billing_branch
/// metrics:
/// - library.googleapis.com/book/borrowed_count
/// Nested message and enum types in `Billing`.
/// Output generated from semantically comparing two versions of a service
/// configuration.
///
/// Includes detailed information about a field that have changed with
/// applicable advice about potential consequences for the change, such as
/// backwards-incompatibility.
/// Generated advice about this change, used for providing more
/// information about how a change will affect the existing service.
/// Classifies set of possible modifications to an object in the service
/// configuration.
/// A descriptor for defining project properties for a service. One service may
/// have many consumer projects, and the service may want to behave differently
/// depending on some properties on the project. For example, a project may be
/// associated with a school, or a business, or a government agency, a business
/// type property on the project may affect how a service responds to the client.
/// This descriptor defines which properties are allowed to be set on a project.
///
/// Example:
///
/// project_properties:
/// properties:
/// - name: NO_WATERMARK
/// type: BOOL
/// description: Allows usage of the API without watermarks.
/// - name: EXTENDED_TILE_CACHE_PERIOD
/// type: INT64
/// Defines project properties.
///
/// API services can define properties that can be assigned to consumer projects
/// so that backends can perform response customization without having to make
/// additional calls or maintain additional storage. For example, Maps API
/// defines properties that controls map tile cache period, or whether to embed a
/// watermark in a result.
///
/// These values can be set via API producer console. Only API providers can
/// define and set these properties.
/// Nested message and enum types in `Property`.
/// `Context` defines which contexts an API requests.
///
/// Example:
///
/// context:
/// rules:
/// - selector: "*"
/// requested:
/// - google.rpc.context.ProjectContext
/// - google.rpc.context.OriginContext
///
/// The above specifies that all methods in the API request
/// `google.rpc.context.ProjectContext` and
/// `google.rpc.context.OriginContext`.
///
/// Available context types are defined in package
/// `google.rpc.context`.
///
/// This also provides mechanism to allowlist any protobuf message extension that
/// can be sent in grpc metadata using “x-goog-ext-<extension_id>-bin” and
/// “x-goog-ext-<extension_id>-jspb” format. For example, list any service
/// specific protobuf types that can appear in grpc metadata as follows in your
/// yaml file:
///
/// Example:
///
/// context:
/// rules:
/// - selector: "google.example.library.v1.LibraryService.CreateBook"
/// allowed_request_extensions:
/// - google.foo.v1.NewExtension
/// allowed_response_extensions:
/// - google.foo.v1.NewExtension
///
/// You can also specify extension ID instead of fully qualified extension name
/// here.
/// A context rule provides information about the context for an individual API
/// element.
/// Selects and configures the service controller used by the service. The
/// service controller handles features like abuse, quota, billing, logging,
/// monitoring, etc.
/// `Distribution` contains summary statistics for a population of values. It
/// optionally contains a histogram representing the distribution of those values
/// across a set of buckets.
///
/// The summary statistics are the count, mean, sum of the squared deviation from
/// the mean, the minimum, and the maximum of the set of population of values.
/// The histogram is based on a sequence of buckets and gives a count of values
/// that fall into each bucket. The boundaries of the buckets are given either
/// explicitly or by formulas for buckets of fixed or exponentially increasing
/// widths.
///
/// Although it is not forbidden, it is generally a bad idea to include
/// non-finite values (infinities or NaNs) in the population of values, as this
/// will render the `mean` and `sum_of_squared_deviation` fields meaningless.
/// Nested message and enum types in `Distribution`.
/// `Documentation` provides the information for describing a service.
///
/// Example:
/// <pre><code>documentation:
/// summary: >
/// The Google Calendar API gives access
/// to most calendar features.
/// pages:
/// - name: Overview
/// content: (== include google/foo/overview.md ==)
/// - name: Tutorial
/// content: (== include google/foo/tutorial.md ==)
/// subpages;
/// - name: Java
/// content: (== include google/foo/tutorial_java.md ==)
/// rules:
/// - selector: google.calendar.Calendar.Get
/// description: >
/// ...
/// - selector: google.calendar.Calendar.Put
/// description: >
/// ...
/// </code></pre>
/// Documentation is provided in markdown syntax. In addition to
/// standard markdown features, definition lists, tables and fenced
/// code blocks are supported. Section headers can be provided and are
/// interpreted relative to the section nesting of the context where
/// a documentation fragment is embedded.
///
/// Documentation from the IDL is merged with documentation defined
/// via the config at normalization time, where documentation provided
/// by config rules overrides IDL provided.
///
/// A number of constructs specific to the API platform are supported
/// in documentation text.
///
/// In order to reference a proto element, the following
/// notation can be used:
/// <pre><code>[fully.qualified.proto.name][]</code></pre>
/// To override the display text used for the link, this can be used:
/// <pre><code>[display text][fully.qualified.proto.name]</code></pre>
/// Text can be excluded from doc using the following notation:
/// <pre><code>(-- internal comment --)</code></pre>
///
/// A few directives are available in documentation. Note that
/// directives must appear on a single line to be properly
/// identified. The `include` directive includes a markdown file from
/// an external source:
/// <pre><code>(== include path/to/file ==)</code></pre>
/// The `resource_for` directive marks a message to be the resource of
/// a collection in REST view. If it is not specified, tools attempt
/// to infer the resource from the operations in a collection:
/// <pre><code>(== resource_for v1.shelves.books ==)</code></pre>
/// The directive `suppress_warning` does not directly affect documentation
/// and is documented together with service config validation.
/// A documentation rule provides information about individual API elements.
/// Represents a documentation page. A page can contain subpages to represent
/// nested documentation set structure.
/// `Endpoint` describes a network endpoint of a service that serves a set of
/// APIs. It is commonly known as a service endpoint. A service may expose
/// any number of service endpoints, and all service endpoints share the same
/// service definition, such as quota limits and monitoring metrics.
///
/// Example service configuration:
///
/// name: library-example.googleapis.com
/// endpoints:
/// # Below entry makes 'google.example.library.v1.Library'
/// # API be served from endpoint address library-example.googleapis.com.
/// # It also allows HTTP OPTIONS calls to be passed to the backend, for
/// # it to decide whether the subsequent cross-origin request is
/// # allowed to proceed.
/// - name: library-example.googleapis.com
/// allow_cors: true
/// Defines the supported values for `google.rpc.ErrorInfo.reason` for the
/// `googleapis.com` error domain. This error domain is reserved for [Service
/// Infrastructure](<https://cloud.google.com/service-infrastructure/docs/overview>).
/// For each error info of this domain, the metadata key "service" refers to the
/// logical identifier of an API service, such as "pubsub.googleapis.com". The
/// "consumer" refers to the entity that consumes an API Service. It typically is
/// a Google project that owns the client application or the server resource,
/// such as "projects/123". Other metadata keys are specific to each error
/// reason. For more information, see the definition of the specific error
/// reason.
/// Message that represents an arbitrary HTTP body. It should only be used for
/// payload formats that can't be represented as JSON, such as raw binary or
/// an HTML page.
///
///
/// This message can be used both in streaming and non-streaming API methods in
/// the request as well as the response.
///
/// It can be used as a top-level request field, which is convenient if one
/// wants to extract parameters from either the URL or HTTP template into the
/// request fields and also want access to the raw HTTP body.
///
/// Example:
///
/// message GetResourceRequest {
/// // A unique request id.
/// string request_id = 1;
///
/// // The raw HTTP body is bound to this field.
/// google.api.HttpBody http_body = 2;
///
/// }
///
/// service ResourceService {
/// rpc GetResource(GetResourceRequest)
/// returns (google.api.HttpBody);
/// rpc UpdateResource(google.api.HttpBody)
/// returns (google.protobuf.Empty);
///
/// }
///
/// Example with streaming methods:
///
/// service CaldavService {
/// rpc GetCalendar(stream google.api.HttpBody)
/// returns (stream google.api.HttpBody);
/// rpc UpdateCalendar(stream google.api.HttpBody)
/// returns (stream google.api.HttpBody);
///
/// }
///
/// Use of this type only changes how the request and response bodies are
/// handled, all other features will continue to work unchanged.
/// A description of a log type. Example in YAML format:
///
/// - name: library.googleapis.com/activity_history
/// description: The history of borrowing and returning library items.
/// display_name: Activity
/// labels:
/// - key: /customer_id
/// description: Identifier of a library customer
/// Logging configuration of the service.
///
/// The following example shows how to configure logs to be sent to the
/// producer and consumer projects. In the example, the `activity_history`
/// log is sent to both the producer and consumer projects, whereas the
/// `purchase_history` log is only sent to the producer project.
///
/// monitored_resources:
/// - type: library.googleapis.com/branch
/// labels:
/// - key: /city
/// description: The city where the library branch is located in.
/// - key: /name
/// description: The name of the branch.
/// logs:
/// - name: activity_history
/// labels:
/// - key: /customer_id
/// - name: purchase_history
/// logging:
/// producer_destinations:
/// - monitored_resource: library.googleapis.com/branch
/// logs:
/// - activity_history
/// - purchase_history
/// consumer_destinations:
/// - monitored_resource: library.googleapis.com/branch
/// logs:
/// - activity_history
/// Nested message and enum types in `Logging`.
/// An object that describes the schema of a \[MonitoredResource][google.api.MonitoredResource\] object using a
/// type name and a set of labels. For example, the monitored resource
/// descriptor for Google Compute Engine VM instances has a type of
/// `"gce_instance"` and specifies the use of the labels `"instance_id"` and
/// `"zone"` to identify particular VM instances.
///
/// Different APIs can support different monitored resource types. APIs generally
/// provide a `list` method that returns the monitored resource descriptors used
/// by the API.
///
/// An object representing a resource that can be used for monitoring, logging,
/// billing, or other purposes. Examples include virtual machine instances,
/// databases, and storage devices such as disks. The `type` field identifies a
/// \[MonitoredResourceDescriptor][google.api.MonitoredResourceDescriptor\] object that describes the resource's
/// schema. Information in the `labels` field identifies the actual resource and
/// its attributes according to the schema. For example, a particular Compute
/// Engine VM instance could be represented by the following object, because the
/// \[MonitoredResourceDescriptor][google.api.MonitoredResourceDescriptor\] for `"gce_instance"` has labels
/// `"instance_id"` and `"zone"`:
///
/// { "type": "gce_instance",
/// "labels": { "instance_id": "12345678901234",
/// "zone": "us-central1-a" }}
/// Auxiliary metadata for a \[MonitoredResource][google.api.MonitoredResource\] object.
/// \[MonitoredResource][google.api.MonitoredResource\] objects contain the minimum set of information to
/// uniquely identify a monitored resource instance. There is some other useful
/// auxiliary metadata. Monitoring and Logging use an ingestion
/// pipeline to extract metadata for cloud resources of all types, and store
/// the metadata in this message.
/// Monitoring configuration of the service.
///
/// The example below shows how to configure monitored resources and metrics
/// for monitoring. In the example, a monitored resource and two metrics are
/// defined. The `library.googleapis.com/book/returned_count` metric is sent
/// to both producer and consumer projects, whereas the
/// `library.googleapis.com/book/num_overdue` metric is only sent to the
/// consumer project.
///
/// monitored_resources:
/// - type: library.googleapis.com/Branch
/// display_name: "Library Branch"
/// description: "A branch of a library."
/// launch_stage: GA
/// labels:
/// - key: resource_container
/// description: "The Cloud container (ie. project id) for the Branch."
/// - key: location
/// description: "The location of the library branch."
/// - key: branch_id
/// description: "The id of the branch."
/// metrics:
/// - name: library.googleapis.com/book/returned_count
/// display_name: "Books Returned"
/// description: "The count of books that have been returned."
/// launch_stage: GA
/// metric_kind: DELTA
/// value_type: INT64
/// unit: "1"
/// labels:
/// - key: customer_id
/// description: "The id of the customer."
/// - name: library.googleapis.com/book/num_overdue
/// display_name: "Books Overdue"
/// description: "The current number of overdue books."
/// launch_stage: GA
/// metric_kind: GAUGE
/// value_type: INT64
/// unit: "1"
/// labels:
/// - key: customer_id
/// description: "The id of the customer."
/// monitoring:
/// producer_destinations:
/// - monitored_resource: library.googleapis.com/Branch
/// metrics:
/// - library.googleapis.com/book/returned_count
/// consumer_destinations:
/// - monitored_resource: library.googleapis.com/Branch
/// metrics:
/// - library.googleapis.com/book/returned_count
/// - library.googleapis.com/book/num_overdue
/// Nested message and enum types in `Monitoring`.
/// Quota configuration helps to achieve fairness and budgeting in service
/// usage.
///
/// The metric based quota configuration works this way:
/// - The service configuration defines a set of metrics.
/// - For API calls, the quota.metric_rules maps methods to metrics with
/// corresponding costs.
/// - The quota.limits defines limits on the metrics, which will be used for
/// quota checks at runtime.
///
/// An example quota configuration in yaml format:
///
/// quota:
/// limits:
///
/// - name: apiWriteQpsPerProject
/// metric: library.googleapis.com/write_calls
/// unit: "1/min/{project}" # rate limit for consumer projects
/// values:
/// STANDARD: 10000
///
///
/// # The metric rules bind all methods to the read_calls metric,
/// # except for the UpdateBook and DeleteBook methods. These two methods
/// # are mapped to the write_calls metric, with the UpdateBook method
/// # consuming at twice rate as the DeleteBook method.
/// metric_rules:
/// - selector: "*"
/// metric_costs:
/// library.googleapis.com/read_calls: 1
/// - selector: google.example.library.v1.LibraryService.UpdateBook
/// metric_costs:
/// library.googleapis.com/write_calls: 2
/// - selector: google.example.library.v1.LibraryService.DeleteBook
/// metric_costs:
/// library.googleapis.com/write_calls: 1
///
/// Corresponding Metric definition:
///
/// metrics:
/// - name: library.googleapis.com/read_calls
/// display_name: Read requests
/// metric_kind: DELTA
/// value_type: INT64
///
/// - name: library.googleapis.com/write_calls
/// display_name: Write requests
/// metric_kind: DELTA
/// value_type: INT64
///
///
/// Bind API methods to metrics. Binding a method to a metric causes that
/// metric's configured quota behaviors to apply to the method call.
/// `QuotaLimit` defines a specific limit that applies over a specified duration
/// for a limit type. There can be at most one limit for a duration and limit
/// type combination defined within a `QuotaGroup`.
/// Specifies the routing information that should be sent along with the request
/// in the form of routing header.
/// **NOTE:** All service configuration rules follow the "last one wins" order.
///
/// The examples below will apply to an RPC which has the following request type:
///
/// Message Definition:
///
/// message Request {
/// // The name of the Table
/// // Values can be of the following formats:
/// // - `projects/<project>/tables/<table>`
/// // - `projects/<project>/instances/<instance>/tables/<table>`
/// // - `region/<region>/zones/<zone>/tables/<table>`
/// string table_name = 1;
///
/// // This value specifies routing for replication.
/// // It can be in the following formats:
/// // - `profiles/<profile_id>`
/// // - a legacy `profile_id` that can be any string
/// string app_profile_id = 2;
/// }
///
/// Example message:
///
/// {
/// table_name: projects/proj_foo/instances/instance_bar/table/table_baz,
/// app_profile_id: profiles/prof_qux
/// }
///
/// The routing header consists of one or multiple key-value pairs. Every key
/// and value must be percent-encoded, and joined together in the format of
/// `key1=value1&key2=value2`.
/// In the examples below I am skipping the percent-encoding for readablity.
///
/// Example 1
///
/// Extracting a field from the request to put into the routing header
/// unchanged, with the key equal to the field name.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // Take the `app_profile_id`.
/// routing_parameters {
/// field: "app_profile_id"
/// }
/// };
///
/// result:
///
/// x-goog-request-params: app_profile_id=profiles/prof_qux
///
/// Example 2
///
/// Extracting a field from the request to put into the routing header
/// unchanged, with the key different from the field name.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // Take the `app_profile_id`, but name it `routing_id` in the header.
/// routing_parameters {
/// field: "app_profile_id"
/// path_template: "{routing_id=**}"
/// }
/// };
///
/// result:
///
/// x-goog-request-params: routing_id=profiles/prof_qux
///
/// Example 3
///
/// Extracting a field from the request to put into the routing
/// header, while matching a path template syntax on the field's value.
///
/// NB: it is more useful to send nothing than to send garbage for the purpose
/// of dynamic routing, since garbage pollutes cache. Thus the matching.
///
/// Sub-example 3a
///
/// The field matches the template.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // Take the `table_name`, if it's well-formed (with project-based
/// // syntax).
/// routing_parameters {
/// field: "table_name"
/// path_template: "{table_name=projects/*/instances/*/**}"
/// }
/// };
///
/// result:
///
/// x-goog-request-params:
/// table_name=projects/proj_foo/instances/instance_bar/table/table_baz
///
/// Sub-example 3b
///
/// The field does not match the template.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // Take the `table_name`, if it's well-formed (with region-based
/// // syntax).
/// routing_parameters {
/// field: "table_name"
/// path_template: "{table_name=regions/*/zones/*/**}"
/// }
/// };
///
/// result:
///
/// <no routing header will be sent>
///
/// Sub-example 3c
///
/// Multiple alternative conflictingly named path templates are
/// specified. The one that matches is used to construct the header.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // Take the `table_name`, if it's well-formed, whether
/// // using the region- or projects-based syntax.
///
/// routing_parameters {
/// field: "table_name"
/// path_template: "{table_name=regions/*/zones/*/**}"
/// }
/// routing_parameters {
/// field: "table_name"
/// path_template: "{table_name=projects/*/instances/*/**}"
/// }
/// };
///
/// result:
///
/// x-goog-request-params:
/// table_name=projects/proj_foo/instances/instance_bar/table/table_baz
///
/// Example 4
///
/// Extracting a single routing header key-value pair by matching a
/// template syntax on (a part of) a single request field.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // Take just the project id from the `table_name` field.
/// routing_parameters {
/// field: "table_name"
/// path_template: "{routing_id=projects/*}/**"
/// }
/// };
///
/// result:
///
/// x-goog-request-params: routing_id=projects/proj_foo
///
/// Example 5
///
/// Extracting a single routing header key-value pair by matching
/// several conflictingly named path templates on (parts of) a single request
/// field. The last template to match "wins" the conflict.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // If the `table_name` does not have instances information,
/// // take just the project id for routing.
/// // Otherwise take project + instance.
///
/// routing_parameters {
/// field: "table_name"
/// path_template: "{routing_id=projects/*}/**"
/// }
/// routing_parameters {
/// field: "table_name"
/// path_template: "{routing_id=projects/*/instances/*}/**"
/// }
/// };
///
/// result:
///
/// x-goog-request-params:
/// routing_id=projects/proj_foo/instances/instance_bar
///
/// Example 6
///
/// Extracting multiple routing header key-value pairs by matching
/// several non-conflicting path templates on (parts of) a single request field.
///
/// Sub-example 6a
///
/// Make the templates strict, so that if the `table_name` does not
/// have an instance information, nothing is sent.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // The routing code needs two keys instead of one composite
/// // but works only for the tables with the "project-instance" name
/// // syntax.
///
/// routing_parameters {
/// field: "table_name"
/// path_template: "{project_id=projects/*}/instances/*/**"
/// }
/// routing_parameters {
/// field: "table_name"
/// path_template: "projects/*/{instance_id=instances/*}/**"
/// }
/// };
///
/// result:
///
/// x-goog-request-params:
/// project_id=projects/proj_foo&instance_id=instances/instance_bar
///
/// Sub-example 6b
///
/// Make the templates loose, so that if the `table_name` does not
/// have an instance information, just the project id part is sent.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // The routing code wants two keys instead of one composite
/// // but will work with just the `project_id` for tables without
/// // an instance in the `table_name`.
///
/// routing_parameters {
/// field: "table_name"
/// path_template: "{project_id=projects/*}/**"
/// }
/// routing_parameters {
/// field: "table_name"
/// path_template: "projects/*/{instance_id=instances/*}/**"
/// }
/// };
///
/// result (is the same as 6a for our example message because it has the instance
/// information):
///
/// x-goog-request-params:
/// project_id=projects/proj_foo&instance_id=instances/instance_bar
///
/// Example 7
///
/// Extracting multiple routing header key-value pairs by matching
/// several path templates on multiple request fields.
///
/// NB: note that here there is no way to specify sending nothing if one of the
/// fields does not match its template. E.g. if the `table_name` is in the wrong
/// format, the `project_id` will not be sent, but the `routing_id` will be.
/// The backend routing code has to be aware of that and be prepared to not
/// receive a full complement of keys if it expects multiple.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // The routing needs both `project_id` and `routing_id`
/// // (from the `app_profile_id` field) for routing.
///
/// routing_parameters {
/// field: "table_name"
/// path_template: "{project_id=projects/*}/**"
/// }
/// routing_parameters {
/// field: "app_profile_id"
/// path_template: "{routing_id=**}"
/// }
/// };
///
/// result:
///
/// x-goog-request-params:
/// project_id=projects/proj_foo&routing_id=profiles/prof_qux
///
/// Example 8
///
/// Extracting a single routing header key-value pair by matching
/// several conflictingly named path templates on several request fields. The
/// last template to match "wins" the conflict.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // The `routing_id` can be a project id or a region id depending on
/// // the table name format, but only if the `app_profile_id` is not set.
/// // If `app_profile_id` is set it should be used instead.
///
/// routing_parameters {
/// field: "table_name"
/// path_template: "{routing_id=projects/*}/**"
/// }
/// routing_parameters {
/// field: "table_name"
/// path_template: "{routing_id=regions/*}/**"
/// }
/// routing_parameters {
/// field: "app_profile_id"
/// path_template: "{routing_id=**}"
/// }
/// };
///
/// result:
///
/// x-goog-request-params: routing_id=profiles/prof_qux
///
/// Example 9
///
/// Bringing it all together.
///
/// annotation:
///
/// option (google.api.routing) = {
/// // For routing both `table_location` and a `routing_id` are needed.
/// //
/// // table_location can be either an instance id or a region+zone id.
/// //
/// // For `routing_id`, take the value of `app_profile_id`
/// // - If it's in the format `profiles/<profile_id>`, send
/// // just the `<profile_id>` part.
/// // - If it's any other literal, send it as is.
/// // If the `app_profile_id` is empty, and the `table_name` starts with
/// // the project_id, send that instead.
///
/// routing_parameters {
/// field: "table_name"
/// path_template: "projects/*/{table_location=instances/*}/tables/*"
/// }
/// routing_parameters {
/// field: "table_name"
/// path_template: "{table_location=regions/*/zones/*}/tables/*"
/// }
/// routing_parameters {
/// field: "table_name"
/// path_template: "{routing_id=projects/*}/**"
/// }
/// routing_parameters {
/// field: "app_profile_id"
/// path_template: "{routing_id=**}"
/// }
/// routing_parameters {
/// field: "app_profile_id"
/// path_template: "profiles/{routing_id=*}"
/// }
/// };
///
/// result:
///
/// x-goog-request-params:
/// table_location=instances/instance_bar&routing_id=prof_qux
/// A projection from an input message to the GRPC or REST header.
/// Source information used to create a Service Config
/// ### System parameter configuration
///
/// A system parameter is a special kind of parameter defined by the API
/// system, not by an individual API. It is typically mapped to an HTTP header
/// and/or a URL query parameter. This configuration specifies which methods
/// change the names of the system parameters.
/// Define a system parameter rule mapping system parameter definitions to
/// methods.
/// Define a parameter's name and location. The parameter may be passed as either
/// an HTTP header or a URL query parameter, and if both are passed the behavior
/// is implementation-dependent.
/// Configuration controlling usage of a service.
/// Usage configuration rules for the service.
///
/// NOTE: Under development.
///
///
/// Use this rule to configure unregistered calls for the service. Unregistered
/// calls are calls that do not contain consumer project identity.
/// (Example: calls that do not contain an API key).
/// By default, API methods do not allow unregistered calls, and each method call
/// must be identified by a consumer project identity. Use this rule to
/// allow/disallow unregistered calls.
///
/// Example of an API that wants to allow unregistered calls for entire service.
///
/// usage:
/// rules:
/// - selector: "*"
/// allow_unregistered_calls: true
///
/// Example of a method that wants to allow unregistered calls.
///
/// usage:
/// rules:
/// - selector: "google.example.library.v1.LibraryService.CreateBook"
/// allow_unregistered_calls: true
/// `Service` is the root object of Google service configuration schema. It
/// describes basic information about a service, such as the name and the
/// title, and delegates other aspects to sub-sections. Each sub-section is
/// either a proto message or a repeated proto message that configures a
/// specific aspect, such as auth. See each proto message definition for details.
///
/// Example:
///
/// type: google.api.Service
/// name: calendar.googleapis.com
/// title: Google Calendar API
/// apis:
/// - name: google.calendar.v3.Calendar
/// authentication:
/// providers:
/// - id: google_calendar_auth
/// jwks_uri: <https://www.googleapis.com/oauth2/v1/certs>
/// issuer: <https://securetoken.google.com>
/// rules:
/// - selector: "*"
/// requirements:
/// provider_id: google_calendar_auth
/// `Visibility` defines restrictions for the visibility of service
/// elements. Restrictions are specified using visibility labels
/// (e.g., PREVIEW) that are elsewhere linked to users and projects.
///
/// Users and projects can have access to more than one visibility label. The
/// effective visibility for multiple labels is the union of each label's
/// elements, plus any unrestricted elements.
///
/// If an element and its parents have no restrictions, visibility is
/// unconditionally granted.
///
/// Example:
///
/// visibility:
/// rules:
/// - selector: google.calendar.Calendar.EnhancedSearch
/// restriction: PREVIEW
/// - selector: google.calendar.Calendar.Delegate
/// restriction: INTERNAL
///
/// Here, all methods are publicly visible except for the restricted methods
/// EnhancedSearch and Delegate.
/// A visibility rule provides visibility configuration for an individual API
/// element.