code: def contains(self, stimtype):
          
          for track in self._segments:
              for component in track:
                  if component.__class__.__name__ == stimtype:
                      return True
          return False
docs: Returns whether the specified stimlus type is a component in this stimulus
  
          :param stimtype: :class:`AbstractStimulusComponent<sparkle.stim.abstract_component.AbstractStimulusComponent>` subclass class name to test for membership in the components of this stimulus
          :type stimtype: str
          :returns: bool -- if the stimtype is in the model