public function getCustomerCustomerGroups($criteria = null, ConnectionInterface $con = null)
    {
        $partial = $this->collCustomerCustomerGroupsPartial && !$this->isNew();
        if (null === $this->collCustomerCustomerGroups || null !== $criteria  || $partial) {
            if ($this->isNew() && null === $this->collCustomerCustomerGroups) {
                // return empty collection
                $this->initCustomerCustomerGroups();
            } else {
                $collCustomerCustomerGroups = ChildCustomerCustomerGroupQuery::create(null, $criteria)
                    ->filterByCustomerGroup($this)
                    ->find($con);

                if (null !== $criteria) {
                    if (false !== $this->collCustomerCustomerGroupsPartial && count($collCustomerCustomerGroups)) {
                        $this->initCustomerCustomerGroups(false);

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

                        $this->collCustomerCustomerGroupsPartial = true;
                    }

                    reset($collCustomerCustomerGroups);

                    return $collCustomerCustomerGroups;
                }

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

                $this->collCustomerCustomerGroups = $collCustomerCustomerGroups;
                $this->collCustomerCustomerGroupsPartial = false;
            }
        }

        return $this->collCustomerCustomerGroups;
    }