Unity engine GameObject extensions : get component, instantiate and clone objects

GameObjectExtensions.cs

public static class GameObjectExtensions {

	/// Try to get component of type T, log error if none found
	public static T GetComponentOrFail<T>(this GameObject gameObject) where T : Component {
		T component = gameObject.GetComponent<T>();
		if (component == null)
			throw ExceptionsUtil.CreateExceptionFormat("No component of type {0} found on {1}.", typeof(T), gameObject);
		return component;
	}

	/// Instantiate prefab / clone game object (helper to avoid casting to GameObject every time)
	public static GameObject Instantiate (this GameObject model) {
		if (model == null) throw ExceptionsUtil.CreateExceptionFormat("Cannot instantiate null model.");
		GameObject gameObjectInstance = Object.Instantiate(model) as GameObject;
		return gameObjectInstance;
	}

	/// Instantiate prefab / clone game object at parent's position
	public static GameObject InstantiateUnder (this GameObject model, Transform parentTr, bool keepLocalPosition = false) {
		GameObject gameObjectInstance = Instantiate(model);
		gameObjectInstance.transform.SetParent(parentTr, false);
		if (!keepLocalPosition)
			gameObjectInstance.transform.localPosition = Vector3.zero;
		return gameObjectInstance;
	}

	/// Duplicate object under the same parent with the same local position, with a new name. This breaks any prefab link.
	public static GameObject Duplicate (this GameObject model, string name) {
		GameObject clone = InstantiateUnder(model, model.transform.parent, true);
		clone.name = name;
		return clone;
	}

}

ExceptionsUtil.CreateExceptionFormat creates a new Exception from a format string + object parameters using string.Format().
I will post a gist for that later.