Method TObjectsDataProvider

catboost/libs/data/objects.cpp:352–390

NCB::TObjectsDataProvider::TObjectsDataProvider(
    // if not defined - call CreateObjectsGroupingFromGroupIds
    TMaybe<TObjectsGroupingPtr> objectsGrouping,
    TCommonObjectsData&& commonData,
    bool skipCheck
) {
    if (objectsGrouping.Defined()) {
        if (!skipCheck) {
            commonData.Check(objectsGrouping);
        }
        ObjectsGrouping = std::move(*objectsGrouping);
    } else {
        if (!skipCheck) {
            commonData.CheckAllExceptGroupIds();
        }
        ObjectsGrouping = MakeIntrusive<TObjectsGrouping>(
            commonData.StoreStringColumns ?
                CreateObjectsGroupingFromGroupIds<TString>(
                    commonData.SubsetIndexing->Size(),
                    commonData.GroupIds.GetMaybeStringData() // Nothing(), Turn off group checks for quantization due to time
                ) :
                CreateObjectsGroupingFromGroupIds<TGroupId>(
                    commonData.SubsetIndexing->Size(),
                    commonData.GroupIds.GetMaybeNumData()
                )
        );
    }
    CommonData = std::move(commonData);

    if ((CommonData.Order == EObjectsOrder::Undefined) && CommonData.Timestamp) {
        const auto& timestamps = *CommonData.Timestamp;
        if ((ObjectsGrouping->GetObjectCount() > 1) &&
            std::is_sorted(timestamps.begin(), timestamps.end()) &&
            (timestamps.front() != timestamps.back()))
        {
            CommonData.Order = EObjectsOrder::Ordered;
        }
    }
}

void NCB::TObjectsDataProvider::SetGroupIds(TConstArrayRef<TGroupId> groupIds) {
    ObjectsGrouping = MakeIntrusive<TObjectsGrouping>(