}
public void unsubscribe(ChatListener chatlistener, TableId id, PlayerId id2) {
if(id==null)
throw new IllegalArgumentException("TableId isn't effective!");
TableChatRoom room=tables.get(id);
if(room==null)
throw new IllegalArgumentException("There exists no table with the given id!");
if(room.getTable().hasAsJoinedPlayer(id2)){
// only players who joined the table, are allowed to unsubscribe their listener
room.unSubscribe(chatlistener);
}
}