void Awake()
    {
        Debug.Assert(Singleton == null, "StateManager Singleton not null on Awake.");
        Singleton = this;

        currentState = new EmotionState();
        currentState.PrintState();
    }
    /// <summary>
    /// Update current emotion state of person on stage based on new inputs.
    /// </summary>
    public void UpdateEmotions(EmotionState emotionChange)
    {
        if (currentState == null)
        {
            return;
        }

        currentState.anger   += emotionChange.anger;
        currentState.sadness += emotionChange.sadness;
        currentState.joy     += emotionChange.joy;
        currentState.envy    += emotionChange.envy;
        currentState.fear    += emotionChange.fear;

        currentState.PrintState();
        UIManager.Singleton.UpdateUI(currentState);
        mapValue();
    }