Type Alias Entries 

pub type Entries = HashMap<String, Entry>;

A type alias represening how Entrys are organized.

Entries is a HashMap composed of key:value pairs of where the value is an Entry and the key is the unique id of its Book, taken from the BookMetadata::id field.

For example:

Entries
 │
 ├── ID: Entry
 ├── ID: Entry
 └── ...

Aliased Type

pub struct Entries { /* private fields */ }