public StateMachineFactory<OPERAND, STATE, EVENTTYPE, EVENT> addTransition(
      STATE preState, STATE postState, Set<EVENTTYPE> eventTypes) {
    return addTransition(preState, postState, eventTypes, null);
  }
@return a NEW StateMachineFactory just like {@code this} with the current
         transition added as a new legal transition.  This overload
         has no hook object.


        Note that the returned StateMachineFactory is a distinct
        object.

        This method is part of the API.

@param preState pre-transition state
@param postState post-transition state
@param eventTypes List of stimuli for the transitions
ambari-server/src/main/java/org/apache/ambari/server/state/fsm/StateMachineFactory.java