public function getDealerProductVersions($criteria = null, ConnectionInterface $con = null)
    {
        $partial = $this->collDealerProductVersionsPartial && !$this->isNew();
        if (null === $this->collDealerProductVersions || null !== $criteria  || $partial) {
            if ($this->isNew() && null === $this->collDealerProductVersions) {
                // return empty collection
                $this->initDealerProductVersions();
            } else {
                $collDealerProductVersions = ChildDealerProductVersionQuery::create(null, $criteria)
                    ->filterByDealerProduct($this)
                    ->find($con);

                if (null !== $criteria) {
                    if (false !== $this->collDealerProductVersionsPartial && count($collDealerProductVersions)) {
                        $this->initDealerProductVersions(false);

                        foreach ($collDealerProductVersions as $obj) {
                            if (false == $this->collDealerProductVersions->contains($obj)) {
                                $this->collDealerProductVersions->append($obj);
                            }
                        }

                        $this->collDealerProductVersionsPartial = true;
                    }

                    reset($collDealerProductVersions);

                    return $collDealerProductVersions;
                }

                if ($partial && $this->collDealerProductVersions) {
                    foreach ($this->collDealerProductVersions as $obj) {
                        if ($obj->isNew()) {
                            $collDealerProductVersions[] = $obj;
                        }
                    }
                }

                $this->collDealerProductVersions = $collDealerProductVersions;
                $this->collDealerProductVersionsPartial = false;
            }
        }

        return $this->collDealerProductVersions;
    }