Method GetHostIdCount

library/cpp/par/par_mr.cpp:108–110

            return Parent->HasHostIds(hostIdSet);
        }
        int GetHostIdCount() override {
            return Parent->GetHostIdCount();
        }
        EDataDistrState UpdateDataDistrState(TVector<TVector<int>>* hostId2Computer) override {
            if (hostId2Computer) {
                hostId2Computer->resize(0);