Pap_Api_Object::getFields PHP Method

        public function getFields()
        {
            return $this->fields;
        }

 protected function fillFieldsToGridRequest($request)
 {
     foreach (parent::getFields() as $field) {
         if ($field->get(self::FIELD_VALUE) != '') {
             $operator = 'L';
             if (in_array($field->get(self::FIELD_NAME), $this->getEqualFields())) {
                 $operator = '=';
             }
             $request->addFilter($field->get(self::FIELD_NAME), $operator, $field->get(self::FIELD_VALUE));
         }
     }
 }