def _unbind(self, rmq_server=None):
        """ Close AMQP connection and unset channel """
        try:
            self.connections[rmq_server].close()
        except AttributeError:
            pass

        self.connections[rmq_server] = None
        self.channels[rmq_server] = None
 Close AMQP connection and unset channel 
src/diamond/handler/rabbitmq_pubsub.py