/**
  * buildParentFromFields
  *
  * @param Doctrine_Table $parent
  * @return void
  */
 protected function buildParentFromFields($parent)
 {
     $parentClass = $this->_options['extends'];
     $parentTable = Doctrine_Core::getTable($parentClass);
     $colsParent = $parentTable->getColumns();
     foreach ($colsParent as $column => $definition) {
         $fieldName = $this->getTable()->getFieldName($column);
         if (in_array($fieldName, array('id', 'parent_id', $this->_options['descendant_column']))) {
             continue;
         }
         $parent->{$fieldName} = $this->_invoker->{$fieldName};
     }
     $parent->{$this->_options['descendant_column']} = $this->getTable()->getTableName();
     $parent->save();
     $this->_invoker->parent_id = $parent->id;
 }