docs: def assertSignalFired(self, signal, *args, **kwargs):
          """
          Assert that a signal was fired with appropriate arguments.
  
          :param signal:
              The :class:`Signal` that should have been fired.
              Typically this is ``SomeClass.on_some_signal`` reference
          :param args:
              List of positional arguments passed to the signal handler
          :param kwargs:
              List of keyword arguments passed to the signal handler
          :returns:
              A 3-tuple (signal, args, kwargs) that describes that event
          """
          event = (signal, args, kwargs)
          self.assertIn(
              event, self._events_seen,
              "\nSignal unexpectedly not fired: {}\n".format(event))
          return event