/**
  *
  * @param \DOMDocument $doc
  * @param \DOMElement $elem
  * @param blaze\collections\ListI[blaze\ds\meta\ColumnMetaData] $primaryKeys
  */
 private function reversePrimaryColumns(\blaze\persistence\meta\ClassDescriptor $elem, $primaryKeys)
 {
     foreach ($primaryKeys as $primaryKey) {
         $id = new \blaze\persistence\meta\IdDescriptor();
         $field = new \blaze\persistence\meta\SingleFieldDescriptor();
         $id->setSingleFieldDescriptor($field);
         $field->setName($this->getMemberName($primaryKey->getName()));
         $field->setType($primaryKey->getClassType());
         $col = new \blaze\persistence\meta\ColumnDescriptor();
         $col->apply($primaryKey);
         $field->setColumnDescriptor($col);
         $elem->addIdentifier($id);
     }
 }
 /**
  *
  * @param \DOMNode $xmlNode
  * @return \blaze\persistence\meta\IdDescriptor 
  */
 private function parseId(\DOMNode $xmlNode)
 {
     $id = new \blaze\persistence\meta\IdDescriptor();
     $id->setSingleFieldDescriptor($this->parseField($xmlNode));
     return $id;
 }