example-voting-app/worker/dotnet/Worker/Messaging/Messages/Message.cs

using System;

namespace Worker.Messaging.Messages
{
    public abstract class Message
    {
        public string CorrelationId { get; set; }  
        
        public abstract string Subject { get; }      

        public Message()
        {
            CorrelationId = Guid.NewGuid().ToString();
        }
    }
}