Сохранность данных при отправке сообщения

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
 
namespace ClassLibrary_wcf
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService_wcf" in both code and config file together.
    [ServiceContract]
    public interface IService_wcf
    {
 
        [OperationContract]
        void msg_set(string set_msg);
 
        [OperationContract]
        string msg_get();
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;
 
namespace ClassLibrary_wcf
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service_wcf" in both code and config file together.
    public class Service_wcf : IService_wcf
    {
 
        public void msg_set(string set_msg)
        {
            msg = set_msg;
        }
 
        public string msg_get()
        {
            return msg;
        }
 
        private string msg {get; set;}
    }
}

 var client = new ServiceReference_2016.Service_wcfClient("BasicHttpBinding_IService_wcf");
 
message_out = "Привет Птичка";
client.msg_set(message_out );
Console.WriteLine("Сообщение отправлено: "+message_out+" !");

var client = new ServiceReference_2016.Service_wcfClient("BasicHttpBinding_IService_wcf");
 
Console.WriteLine("Сообщение получено: "+client.msg_get());