Starts ZMQ monitor for debugging purposes.
        :return:

def _start_zmq_monitor(self):
        '''
        Starts ZMQ monitor for debugging purposes.
        :return:
        '''
        # Socket monitor shall be used the only for debug
        # purposes so using threading doesn't look too bad here

        if HAS_ZMQ_MONITOR and self.opts['zmq_monitor']:
            log.debug('Starting ZMQ monitor')
            import threading
            self._w_monitor = ZeroMQSocketMonitor(self._socket)
            threading.Thread(target=self._w_monitor.start_poll).start()
            log.debug('ZMQ monitor has been started started')