*/ interface CacheInterface { /** * Write data to storage. * * @param string $id * @param string $data * * @return string */ public function save($id, $data); /** * Fetch data from file. * * @param string $id */ public function fetch($id); /** * Delete data from storage. * * @param string $id */ public function delete($id); /** * Data exists in storage. * * @param string $id * * @return bool */ public function exists($id); }