code: def all_state_variables_written(self):
          '''
              list(StateVariable): List all of the state variables written
          '''
          all_state_variables_written = [f.all_state_variables_written() for f in self.functions + self.modifiers]
          all_state_variables_written = [item for sublist in all_state_variables_written for item in sublist]
          return list(set(all_state_variables_written)f all_state_variables_written(self):
          '''
              list(StateVariable): List all of the state variables written
          '''
          all_state_variables_written = [f.all_state_variables_written() for f in self.functions + self.modifiers]
          all_state_variables_written = [item for sublist in all_state_variables_written for item in sublist]
          return list(set(all_state_variables_written))
docs: list(StateVariable): List all of the state variables written