'Synchronous Put operation.
Args:
entities: An iterable of user-level entity objects.
Returns:
A list of user-level key objects, corresponding 1:1 to the
argument entities.
NOTE: If any of the entities has an incomplete key, this will
*not* patch up those entities with the complete key.'

def put(self, entities):

    return self.async_put(None, entities).get_result()
