protected EnumSet<S> lastStates() {
        assertSteps();
        return EnumSet.of(Iterables.getLast(steps.keySet()));
    }
protected EnumSet < S > lastStates ( ) { assertSteps ( ) ; return EnumSet . of ( Iterables . getLast ( steps . keySet ( ) ) ) ; }
@return the last state(s) which is the state of the last added step by default.