Cancel a call to consume() happening in another thread

        This could take up to DashiConnection.consumer_timeout to complete.

        @param block: if True, waits until the consumer has returned

def cancel(self, block=True):
        """Cancel a call to consume() happening in another thread

        This could take up to DashiConnection.consumer_timeout to complete.

        @param block: if True, waits until the consumer has returned
        """
        if self._consumer:
            self._consumer.cancel(block=block)