docs: def emit(self, signal, message, analysis_id):
          """Emit signal to main.
  
          Args:
              signal: Name of the signal to be emitted.
              message: Message to be sent.
              analysis_id: Identifies the instance of this analysis.
  
          """
  
          log.debug('kernel {} zmq send ({}): {}'
                    ''.format(analysis_id, signal, message))
          self.zmq_publish.send(json.dumps({
              'analysis_id': analysis_id,
              'frame': {'signal': signal, 'load': message},
          }, default=json_encoder_default).encode('utf-8'))