def _add_help_noop_and_quit_transitions(self):
        """HELP, NOOP and QUIT should be possible from everywhere so we
        need to add these transitions to all states configured so far."""
        states = set()
        for state_name in self.state.known_states():
            if state_name not in ['new', 'finished']:
                states.add(state_name)
        for state in states:
            self._add_state(state, 'NOOP',  state)
            self._add_state(state, 'HELP',  state)
            self._add_state(state, 'QUIT',  'finished')
HELP, NOOP and QUIT should be possible from everywhere so we
        need to add these transitions to all states configured so far.