Python 3.9 is now generally available.

google.appengine.datastore.datastore_pbs.get_v1_mutation_key_and_entity

Returns the v1 key and entity for a v1 mutation proto, if applicable.

v1_mutation A googledatastore.Mutation.

A tuple (googledatastore.Key for this mutation, googledatastore.Entity or None if the mutation is a deletion).