Thread safe and lazy initialized implementation of Singleton design pattern in C#.

Singleton

public class Class1
{
    private Class1() { }
    
    public static Class1 Instance
    {
        get { return Class1Creator.instance; }
    }
    
    private class Class1Creator
    {
        static Class1Creator() { }
    
        internal static readonly Class1 instance = new Class1();
    }
}