/**
  * transform
  *
  * @param KVDthes_term $thes
  * @return EasyRdf_Resource
  */
 public function transform(KVDthes_Term $term)
 {
     if (!$term->isPreferredTerm()) {
         $term = $term->getPreferredTerm();
     }
     if ($term->getType()->getId() == 'NL') {
         $type = 'skos:Collection';
     } else {
         $type = 'skos:Concept';
     }
     try {
         $uri = $this->genTermUri($term);
         $res = $this->graph->resource($uri, $type);
     } catch (InvalidArgumentException $e) {
         $res = $this->graph->newBNode($type);
     }
     $thes = $term->getThesaurus();
     try {
         $thes_uri = $this->genThesaurusUri($thes);
         $thres = $this->graph->resource($thes_uri);
         $res->add('skos:inScheme', $thres);
     } catch (InvalidArgumentException $e) {
         // Kennen geen uri voor de thesaurus.
     }
     $res->add('skos:prefLabel', $term->getTerm());
     if ($term->hasRelations(KVDthes_Relation::REL_UF)) {
         $rels = $term->getNonPreferredTerms();
         foreach ($rels as $rel) {
             $res->add('skos:altLabel', $rel->getTerm());
         }
     }
     if ($term->hasRelations(KVDthes_Relation::REL_NT)) {
         $rels = $term->getNarrowerTerms();
         foreach ($rels as $rel) {
             if ($rel->getType()->getId() == 'NL') {
                 $nts = $rel->getNarrowerTerms();
             } else {
                 $nts = new KVDthes_DomainObjectCollection(array($rel));
             }
             foreach ($nts as $nt) {
                 if ($term->getType()->getId() == 'NL') {
                     $rel_uri = 'skos:member';
                 } else {
                     $rel_uri = 'skos:narrower';
                 }
                 $uri = $this->genTermUri($nt);
                 $ntres = $this->graph->resource($uri);
                 $res->add($rel_uri, $ntres);
             }
         }
     }
     if ($term->getType()->getId() != 'NL' && $term->hasRelations(KVDthes_Relation::REL_BT)) {
         $bt = $term->getBroaderTerm();
         while ($bt->getType()->getId() == 'NL') {
             $bt = $bt->getBroaderTerm();
         }
         $uri = $this->genTermUri($bt);
         $bt = $this->graph->resource($uri);
         $res->add('skos:broader', $bt);
     }
     if ($term->hasRelations(KVDthes_Relation::REL_RT)) {
         $rels = $term->getRelatedTerms();
         foreach ($rels as $rel) {
             $uri = $this->genTermUri($rel);
             $rt = $this->graph->resource($uri);
             $res->add('skos:related', $rt);
         }
     }
     if ($term->getScopeNote() != '') {
         $res->add('skos:definition', $term->getScopeNote());
     }
     if ($term->getIndexingNote() != '') {
         $res->add('skos:scopeNote', $term->getIndexingNote());
     }
     if ($term->getHistoryNote() != '') {
         $res->add('skos:historyNote', $term->getHistoryNote());
     }
     if ($term->getSourceNote() != '') {
         $res->add('dc:source', $term->getSourceNote());
     }
     return $res;
 }