public void ChangeState(IState1 newState)
    {
        Debug.Log("ChangeState");

        if (currentState != null)
        {
            currentState.Exit();
        }

        previousState = currentState;
        currentState  = newState;
        currentState.Enter();

        Debug.Log(currentState);
    }
 public void ReturnToPreviousState()
 {
     currentState = previousState;
 }