/**
  * Genera el json con los registros que vienen de la coleccion 
  *
  */
 public function generateJson($record)
 {
     $json = new JsonObject();
     $json->addValue('id', $record->getId());
     $previous = array();
     foreach ($this->fields as $field) {
         if (!in_array($field->completeName(), $previous)) {
             $json->addValue($field->completeName(), $field->getValue($record));
         }
         $previous[count($previous)] = $field->getName();
     }
     return $json;
 }