code: def send_to_observer(self, msg, frm):
          
          logger.debug("{} sending message to observer: {}".
                       format(self, (msg, frm)))
          self._observer.append_input(msg, frm)
docs: Send the message to the observer.
  
          :param msg: the message to send
          :param frm: the name of the node which sent this `msg`