code: def get_partition_owner(self, partition_id):
          
          if partition_id not in self.partitions:
              self._do_refresh()
          return self.partitions.get(partition_id, None)
docs: 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.