c# not disposing new parameter

gistfile1.txt

namespace Disposetest
{

    class test : IDisposable
    {
        public void Dispose()
        {
            Console.WriteLine("disposing");
        }
    }


    class Program
    {

        static void magic(test instance)
        { }

        static void Main(string[] args)
        {
            Console.WriteLine("first run");
            magic(new test());
            Console.WriteLine("second run");
            using (var instance = new test())
                magic(instance);

            Console.ReadLine();
        }
    }
}