public Leave(User sender, string message, Chatroom chatroom, bool doBroadcast)
: base(sender, message, chatroom, doBroadcast)
{
}
public Management(User sender,User recipient,Chatroom Mgmt_Chatroom,List<Chatroom> Chatrooms)
: base(sender,string.Empty,Mgmt_Chatroom,false)
{
this.Chatrooms = Chatrooms;
this.recipient = recipient;
}