/// <summary>
 /// Update the sender's local player count from the network. 
 /// </summary>
 public static void UpdateFromNetwork(this NetworkGamer sender, PacketReader reader)
 {
     // ignore any packets with the wrong header (possibly delayed packets from a previous exchange)
     if (reader.ReadByte() == PacketHeader.LOBBY_DATA) sender.Tag = reader.ReadInt32();
 }