Method AddCancel

library/cpp/neh/netliba.cpp:210–217

                }

                void AddCancel(const TGUID& guid) override {
                    UpdateInFly();
                    TInFly::iterator it = InFly_.find(guid);

                    if (it != InFly_.end() && it->second->SetNotified()) {
                        it->second->NotifyError("Canceled (before ack)");
                    }
                }

                void AddRequestAck(const TGUID& guid) override {
                    UpdateInFly();