File Stream C#

using System;
using System.Collections.Generic;
using System.Text;
using System.Collections.ObjectModel;
using System.IO;
namespace AntEater.Runtime.Tests.Services.Transformation
{
    /// 
    /// Provides a set of Utilities.
    /// 

    internal class Utilities
    {
        /// 
        /// Copies an Stream into another Stream.
        /// 

        /// From.
        /// To.
        /// The buffersize.
        /// The number of Bytes copied.
        public static long CopyStream(Stream from, Stream to, int buffersize) {
            byte[] buffer = new byte[buffersize];
            long totalBytesCopied = 0;
            int bytesRead = 0;
            bytesRead = from.Read(buffer, 0, buffersize);
            while(bytesRead > 0){
                to.Write(buffer, 0, bytesRead);
                totalBytesCopied += bytesRead;
                bytesRead = from.Read(buffer, 0, buffersize);
            }
            return totalBytesCopied;
        }
    }
}