public void SetLayerRecursivelyNull()
 {
     Assert.Throws(typeof(System.ArgumentNullException), () =>
     {
         GameObjectExtensions.SetLayerRecursively(null, waterLayer);
     });
 }
 public void SetLayerRecursivelyCacheNull()
 {
     Assert.Throws(typeof(System.ArgumentNullException), () =>
     {
         Dictionary <GameObject, int> layerCache;
         GameObjectExtensions.SetLayerRecursively(null, waterLayer, out layerCache);
     });
 }