public CreateReader(EndpointInfo ei, int sn)
 {
     h = new Header (CommandId.Create, EntityKind.DataReader, sn);
     b = ei;
 }
 public CreateTopic(TopicInfo b, int sn)
 {
     h = new Header (CommandId.Create, EntityKind.Topic, sn);
     this.b = b;
 }
 public CommandReply(Header h, ReplyBody b)
 {
     this.h = h;
     this.b = b;
 }