protected function addProductTrack(ProductTrack $productTrack) { $this->ids[$productTrack->getProductTrackId()] = $productTrack; if (!array_key_exists($productTrack->getProductId(), $this->productIds)) { $this->productIds[$productTrack->getProductId()] = array(); } $this->productIds[$productTrack->getProductId()][] = $productTrack; }