An RPC error, as defined in the RPC specification.
A struct that contains the same data as Message::Response. Used to save redundant matches against a Message that is known to be a Message::Response.
Message::Response
match
Message
An RPC message. One of [Request, Response, Notification].
Request
Response
Notification
An RPC request ID. Can be a string (Str) or an integer (Int).
Str
Int