/// <summary>
 /// Removes a function of type RPGStatModifierEvent to the OnValueChange delagate.
 /// </summary>
 public void RemoveValueListener(RPGStatModifierEvent func)
 {
     _onValueChange -= func;
 }
 /// <summary>
 /// Adds a function of type RPGStatModifierEvent to the OnValueChange delagate.
 /// </summary>
 public void AddValueListener(RPGStatModifierEvent func)
 {
     _onValueChange += func;
 }