MessageSender Link is now open - perform message send
        on all pending messages.
        Will return True if operation successful and client can remain open for
        further work.

        :rtype: bool

def _client_run(self):
        """MessageSender Link is now open - perform message send
        on all pending messages.
        Will return True if operation successful and client can remain open for
        further work.

        :rtype: bool
        """
        # pylint: disable=protected-access
        self._waiting_messages = 0
        self._pending_messages = self._filter_pending()
        if self._backoff and not self._waiting_messages:
            _logger.info("Client told to backoff - sleeping for %r seconds", self._backoff)
            self._connection.sleep(self._backoff)
            self._backoff = 0
        self._connection.work()
        return True