gistfile1.txt

using System;

namespace Blah {

    [AttributeUsage(AttributeTargets.Parameter, AllowMultiple = true)]
    public sealed class ValidatedNotNullAttribute : Attribute
    {
    }
    
    public static class Guard
    {
        public static void ArgumentNotNull([ValidatedNotNull] object argumentValue, string argumentName)
        {
            if (argumentValue == null)
            {
                throw new ArgumentNullException(argumentName);
            }
        }
    }
}