<?phpnamespace Illuminate\Cache;use Illuminate\Contracts\Cache\Store;// a name space to declareclass NullStore extends TaggableStore implements Store{ use RetrievesMultipleKeys;// use a traits ,this is a Retrieves MultipleKeys /** * The array of stored values. * * @var array */ protected $storage = [];// a store array to keep values. /** * Retrieve an item from the cache by key. * * @param string $key * @return mixed */ public function get($key) { // }// struct method /** * Store an item in the cache for a given number of minutes. * * @param string $key * @param mixed $value * @param int $minutes * @return void */ public function put($key, $value, $minutes) { // }//struct method /** * Increment the value of an item in the cache. * * @param string $key * @param mixed $value * @return int */ public function increment($key, $value = 1) { // }//struct method /** * Increment the value of an item in the cache. * * @param string $key * @param mixed $value * @return int */ public function decrement($key, $value = 1) { // }//struct method /** * Store an item in the cache indefinitely. * * @param string $key * @param mixed $value * @return void */ public function forever($key, $value) { // }//struct method /** * Remove an item from the cache. * * @param string $key * @return void */ public function forget($key) { // }//struct method /** * Remove all items from the cache. * * @return void */ public function flush() { // }//struct method /** * Get the cache key prefix. * * @return string */ public function getPrefix() { return ''; }//struct method}