def get_partition_owner(self, partition_id):
if partition_id not in self.partitions:<EOL><INDENT>self._do_refresh()<EOL><DEDENT>return self.partitions.get(partition_id, None)<EOL>
Gets the owner of the partition if it's set. Otherwise it will trigger partition assignment.

:param partition_id: (int), the partition id.
:return: (:class:`~hazelcast.core.Address`), owner of partition or ``None`` if it's not set yet.