My Personal and Also Another Approach to Handling the Singleton Design Pattern

using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;

// Copyright UZi
namespace UZi.Singleton
{
    /// <summary>
    /// Generic class for building an instance of T.
    /// </summary>
    /// <typeparam name="T">The type of the singleton class.</typeparam>
    public class SingletonBuilder<T> : ISingletonBuilder<T> 
        where T : class
    {
        // should also be protected
        protected SingletonBuilder() { }

        /// <summary>
        /// Creates an instance of T.
        /// </summary>
        /// <param name="checker">A delegate of type 'SingletonClassConstructorArgsChecker' to check parameter 'args' 
        /// or null if constructor of T don't have arguments.</param>
        /// <param name="args">The arguments for the constructor of T or null if the constructor don't have any argument.</param>
        /// <returns>An (initialized) instance of T.</returns>
        public T BuildSingleton(SingletonClassConstructorArgsChecker checker, object[] args)
        {
            // perform some checks...
            if (typeof(T).IsAbstract) throw new Exception("Can't create an instance of an abstract class!");
            if ((typeof(T).GetConstructors()).Length > 0) throw new InvalidOperationException(
               "Operation is invalid for a class with a public constructor!");
            if (checker == null && (args != null && args.Length > 0)) throw new ArgumentException(
                "If length of parameter 'args' greater than zero parameter 'checker' don't be null!");
            
            if ((checker != null && checker(args)) || (checker == null))
            {
                return (T)Activator.CreateInstance(typeof(T), BindingFlags.CreateInstance |
                        BindingFlags.Instance |
                            BindingFlags.NonPublic, null, args, null);
            }
            else
                throw new ArgumentException();
        }
        
    }
}