/// <summary>
/// Returns event if there wasn't one before
/// </summary>
/// <param name="unityAction"></param>
/// <param name="action"></param>
/// <returns></returns>
public static UnityEventAction <T0> operator +(UnityEventAction <T0> unityAction, Action <T0> action)
{
if (unityAction == null)
{
unityAction = new UnityEventAction <T0>();
}
unityAction._action += action;
return(unityAction);
}
