Version: 5.6
public static void IsNull (T value);
public static void IsNull (T value, string message);

説明

値が null であるアサート

public class AssertionExampleClass : MonoBehaviour
{
    MyClass myClassReference;
    void Update()
    {
        //Make sure the myClassReference reference is never set
        Assert.IsNull(myClassReference);
    }
}