.NET debugging lambda

Function.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using Amazon.Lambda.Core;

// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
//[assembly: LambdaSerializer(typeof(Amazon.Lambda.Serialization.SystemTextJson.DefaultLambdaJsonSerializer))]

namespace Debugging
{
    public class Function
    {
        
        /// <summary>
        /// A simple function that takes a string and does a ToUpper
        /// </summary>
        /// <param name="input"></param>
        /// <param name="context"></param>
        /// <returns></returns>
        public Stream FunctionHandler(System.IO.Stream input, ILambdaContext context)
        {
            string result;
            using (var memoryStream = new MemoryStream())
            {
                input.CopyTo(memoryStream);
                byte[] arr = memoryStream.ToArray();
                result = BitConverter.ToString(arr);
            }
            
            MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(result));
            return ms;
        }
    }
}