anchor.diff:                  let sender = mailbox.Sender()
                   match state', message with
                   | Some (_, userMonitor), Connect(x,y) ->
  +                    printfn "Connect in server: %A" userMonitor
                       let user = userMonitor.Connect x y
  +                    printfn "Result in user %A" user
                       sender <! user
                   | Some (roomMonitor, _), GetRoomList ->
                       let roomList = roomMonitor.GetRoomList()
  
positive.code:             let! message = mailbox.Receive()
              match message with
              | UserSays (message, userName) ->
                  notifyUsers state (UserSaid (userName, message, (state.RoomName)))
                  return! loop state
              | Join(userConnection) ->
                  printfn "In room joining %A" message
                  notifyUsers state (UserJoinedRoom (state.RoomName, userConnection.UserName))
                  printfn "Hello"
                  return! loop {state with ConnectedUsers = state.ConnectedUsers |> Map.add userConnection.UserName userConnection}
          }
  
negative.code:                 let sender = mailbox.Sender()
                  match message with
                  | UserMonitorMessage.Connect (userName, notificationFun) ->
                      printfn "Connecting user in user monitor"
                      match state.UserMap |> Map.tryFind userName with
                      | Some user ->
                          user.Reconnect notificationFun
  