VladimirReshetnikov

using System;
using N; // This using directive is unused, but cannot be simply removed

static class C
{
    static void Ex(this string x) { }
    static void Foo(Action<string> x, int y) { }
    static void Foo(Action<string> x, string y) { }
    static void Foo(Action<string> x, object y) { }
    static void Foo(Action<int> x, int y) { }