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

async def _client_run_async(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
        async with self._pending_messages_lock:
            self._pending_messages = await self._filter_pending_async()
        if self._backoff and not self._waiting_messages:
            _logger.info("Client told to backoff - sleeping for %r seconds", self._backoff)
            await self._connection.sleep_async(self._backoff)
            self._backoff = 0
        await asyncio.shield(self._connection.work_async())
        return True