code: def step(self):
          
          current_state = max(self.infos(type=State),
                              key=attrgetter('creation_time'))
          current_contents = float(current_state.contents)
          new_contents = 1 - current_contents
          info_out = State(origin=self, contents=new_contents)
          transformations.Mutation(info_in=current_state, info_out=info_out)
docs: Prompt the environment to change.