'Fetch objects into another repository.
:param target: The target repository
:param determine_wants: Optional function to determine what refs to
fetch.
:param progress: Optional progress function
:return: The local refs'

def fetch(self, target, determine_wants=None, progress=None):

    if (determine_wants is None):
        determine_wants = target.object_store.determine_wants_all
    target.object_store.add_objects(self.fetch_objects(determine_wants, target.get_graph_walker(), progress))
    return self.get_refs()
