Enum with base type counter-example

Test.cs

using System;

static class Program
{
    public static void Test<TEnum>()
        where TEnum : struct
    {
        Console.WriteLine(typeof(TEnum).IsEnum);
    }

    public static void Test<TEnum>(this string text)
        where TEnum : struct
    {
        if (!typeof(TEnum).IsEnum)
        {
            Console.WriteLine("Not an enum");
            return;
        }

        Console.WriteLine("Is an enum");
    }

    public enum Test1
    {
        Value1,
        Value2,
    }

    public enum Test2 : byte
    {
        Value3,
        Value4,
    }

    static void Main(string[] args)
    {
        Test<Test1>();
        Test<Test2>();
        "".Test<Test1>();
        "".Test<Test2>();
    }
}