ErrorArgs.cs

using System;

namespace XGain
{
    public class ErrorArgs : EventArgs
    {
        public ErrorArgs(Exception ex)
        {
            Date = DateTime.Now;
            Exception = ex;
        }

        public DateTime Date { get; set; }
        public Exception Exception { get; set; }
    }
}

OnNewMessage.cs

using System;
using XGain.Sockets;

namespace XGain
{
    public class MessageArgs : EventArgs
    {
        public ISocket Client { get; set; }
        public object UserToken { get; set; }
        public byte[] RequestBytes { get; set; }
    }
}

OnStart.cs

using System;
using System.Net;

namespace XGain
{
    public class StartArgs : EventArgs
    {
        public StartArgs(ProcessingType processingType, EndPoint localEndpoint)
        {
            ProcessingType = processingType;
            LocalEndpoint = localEndpoint;
        }

        public EndPoint LocalEndpoint { get; set; }
        public ProcessingType ProcessingType { get; set; }
    }
}