public delegate void SourceResolveCb (Source source, uint operation_id, owned Media media, Error? error)
Prototype for the callback passed to resolve.
If the URI did not resolve to a valid media record,
media will be null. If there was an error
error will be set.
media is non-null, ownership of it is transferred to the callback, and it must be freed
afterwards using unref.
a data transfer object
possible Error generated at processing
user data passed to resolve