C#中一个好的线程安全单例通用模板模式是什么

using System;

public class Singleton<T> where T : class
{
    private static Lazy<T> _instance = new Lazy<T>(() =>
    {
        return new T();
    });

    public static T Instance => _instance.Value;

    private Singleton(T initialValue)
    {
        _instance.Value = initialValue;
    }

    ~Singleton()
    {
        _instance = null;
    }

    private static void CheckState()
    {
        if (typeof(T) == typeof(T) && _instance.IsValueCreated && (_instance.Value == _instance.Value))
        {
            throw new InvalidOperationException(String.Format("This type '{0}' has been registered multiple times in '{1}'.", typeof(T), typeof(Singleton<T>).AssemblyQualifiedName));
        }
    }
}

public class MyClass
{
    public MyClass()
    {
        SingletonFactory.Instance.Instance.StartMethod();
    }
}

public class SingletonFactory
{
    public static Singleton<MyClass> Instance { get; set; } = new Singleton<MyClass>();
}