anchor.diff:  
     UsersUpdated = dict:store(Key, NewDescriptor, Users),
   
  -  Check = dict:fetch(Key, UsersUpdated),
  -
     StateUpdated = State#state{clientsOnlineDict = UsersUpdated},
     StateUpdated;
   
  
positive.code:   AllClients = dict:fetch_keys(State#state.clientsOnlineDict),
  
  
    OnlineIds = lists:filter(
      fun({Addr, Port}) -> (Addr /= SenderAddress) or (Port /= SenderPort) end,
      AllClients),
  
    ok = lists:foreach(fun(Id) -> send_to(Id, Msg, State) end, OnlineIds).
  
  send_to(_Id = {Addr, Port}, Msg, State) ->
    Client = dict:fetch({Addr, Port}, State#state.clientsOnlineDict),
    Sock = Client#client.sock,
    ok = gen_tcp:send(Sock, Msg#message.text).
  
negative.code: %% API
  -export([
    process_request/3,
    command_to_atom/1,
  send_last_messages/2
  ]).
  
  -spec command_to_atom/1 :: (string()) -> atom().
  