public static int Read(byte[] buf, int c, Heartbeat hb)
 {
     hb.SequenceNum = BitConverter.ToUInt32(buf, 0);
     c += 4;
     return c;
 }
 public static Heartbeat Read(byte[] buf)
 {
     var hb = new Heartbeat();
     Read(buf, 0, hb);
     return hb;
 }