C# - Extension Method

namespace ExtensionMethod
{
    public interface IMyInterface
    {
        void foo(bool b);
    }
    public static class MyInterfaceExt
    {
        public static void Disabled(this IMyInterface c, bool b)
        {
            c.foo(b);
        }
    }

    class MyCls : IMyInterface
    {
        public void foo(bool b)
        {
            Debugger.Break();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            MyCls c = new MyCls();
            c.Disabled(true);
        }
    }
}