/// <summary>
/// Adds a ValueController to the ValueControllerChain.
/// </summary>
/// <param name="layer">The layer of the ValueController</param>
/// <param name="valueController">The ValueController.</param>
/// <remarks>ValueController on the same layer are started simultaneously.</remarks>
public void AddValueController(int layer, ValueController <T> valueController)
{
this.AddValueController(layer, valueController, null);
}