code: def transition(self, duration, is_on=None, **kwargs):
          
          self._cancel_active_transition()
  
          dest_state = self._prepare_transition(is_on, **kwargs)
          total_steps = self._transition_steps(**dest_state)
          state_stages = [self._transition_stage(step, total_steps, **dest_state)
                          for step in range(total_steps)]
          pwm_stages = [self._get_pwm_values(**stage)
                        for stage in state_stages]
          callback = partial(self._transition_callback, is_on)
          self._active_transition = Transition(self._driver, duration,
                                               state_stages, pwm_stages,
                                               callback)
  
          TransitionManager().execute(self._active_transition)
  
          return self._active_transition
docs: Transition to the specified state of the led.
  
          If another transition is already running, it is aborted.
  
          :param duration: The duration of the transition.
          :param is_on: The on-off state to transition to.
          :param kwargs: The state to transition to.