public function databaseBackup($site, $env, $db, $backupId)
{
$variables = array('site' => $site, 'env' => $env, 'db' => $db, 'id' => $backupId);
$request = $this->get(array('{+base_path}/sites/{site}/envs/{env}/dbs/{db}/backups/{id}.json', $variables));
return new Response\DatabaseBackup($request);
}