void DocumentSourceLookUp::detachFromOperationContext() {
    if (_pipeline) {
        // We have a pipeline we're going to be executing across multiple calls to getNext(), so we
        // use Pipeline::detachFromOperationContext() to take care of updating '_fromExpCtx->opCtx'.
        _pipeline->detachFromOperationContext();
        invariant(_fromExpCtx->opCtx == nullptr);
    } else if (_fromExpCtx) {
        _fromExpCtx->opCtx = nullptr;
    }
}
void DocumentSourceLookUp::detachFromOperationContext() {
    if (_pipeline) {
         
         
        _pipeline->detachFromOperationContext();
        invariant(_fromExpCtx->opCtx == nullptr);
    } else if (_fromExpCtx) {
        _fromExpCtx->opCtx = nullptr;
    }
}