code: @Override
      public void init(final Class<? extends State> stateClass) throws InitializationException {
          try {
              currentState = getState(stateClass);
              change.firePropertyChange(STATE_CHANGE, null, currentState.getClass());
          } catch (NotAvailableException ex) {
              throw new InitializationException(this, ex);
          }
      }
docs: Defines the initial state of the state machine.
  
  @param stateClass
  @throws InitializationException