public function getPersonFunctionLinks($criteria = null, ConnectionInterface $con = null)
    {
        $partial = $this->collPersonFunctionLinksPartial && !$this->isNew();
        if (null === $this->collPersonFunctionLinks || null !== $criteria  || $partial) {
            if ($this->isNew() && null === $this->collPersonFunctionLinks) {
                // return empty collection
                $this->initPersonFunctionLinks();
            } else {
                $collPersonFunctionLinks = ChildPersonFunctionLinkQuery::create(null, $criteria)
                    ->filterByPersonFunction($this)
                    ->find($con);

                if (null !== $criteria) {
                    if (false !== $this->collPersonFunctionLinksPartial && count($collPersonFunctionLinks)) {
                        $this->initPersonFunctionLinks(false);

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

                        $this->collPersonFunctionLinksPartial = true;
                    }

                    reset($collPersonFunctionLinks);

                    return $collPersonFunctionLinks;
                }

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

                $this->collPersonFunctionLinks = $collPersonFunctionLinks;
                $this->collPersonFunctionLinksPartial = false;
            }
        }

        return $this->collPersonFunctionLinks;
    }