reverse ??

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace System.Linq
{
    public static class LinqExtensions
    {
        public static TResult GetProperty<TSource, TResult>(this TSource source, Func<TSource, TResult> selector)
        {
            if (source == null)
            {
                return default(TResult);
            }
            if (selector == null)
            {
                throw new ArgumentNullException("selector can't be null");
            }
            return selector(source);
        }
    }
}