/**
  * Retrieve the field
  *
  * @param int $id
  * @return \Field
  */
 public function getFieldById($id)
 {
     list($this->last_result, $this->last_error) = $this->rest_client->get($this->path . '/' . $id);
     $this->erreur = $this->getError($this->last_result, $this->last_error);
     if (isset($this->erreur)) {
         return null;
     }
     if (!Field::isJsonValid($this->last_result)) {
         $this->erreur = $this->jsonErrorMessage();
         return null;
     }
     return new Field($this->last_result);
 }