Lists the commands visible to this client.

        Commands are returned in lexicographical order.

        :rtype: :class:`.Command` iterator

def list_commands(self, page_size=None):
        """
        Lists the commands visible to this client.

        Commands are returned in lexicographical order.

        :rtype: :class:`.Command` iterator
        """
        params = {}

        if page_size is not None:
            params['limit'] = page_size

        return pagination.Iterator(
            client=self._client,
            path='/mdb/{}/commands'.format(self._instance),
            params=params,
            response_class=mdb_pb2.ListCommandsResponse,
            items_key='command',
            item_mapper=Command,
        )