public static T MapTo <T, T2>(this MessagePack <T2> pack) where T : MessagePack <T2>, new() => new T()
 {
     Name = pack.Name, DateTime = pack.DateTime, Message = pack.Message
 };
 public static T MapTo <T>(this MessagePack pack) where T : MessagePack, new() => new T()
 {
     Name = pack.Name, DateTime = pack.DateTime
 };