C#でprivateクラス

using UnityEngine;
using System.Collections;

private class NewBehaviourScript : MonoBehaviour {

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
	
	}
}

結果

error CS1527: Namespace elements cannot be explicitly declared as private, protected or protected internal

と怒られる！

private と protected と protected internalはダメのようだ。