Handle for a Resource's unique ID.
The RID type is used to access the unique integer ID of a resource. They are opaque, which means they do not grant access to the associated resource by themselves. They are used by and with the low-level Server classes such as VisualServer.
get_id ( )
Creates a new RID instance with the ID of a given resource. When not handed a valid resource, silently stores the unused ID 0.
int get_id ( )
Returns the ID of the referenced resource.