Stores data in the persistent cache.
string $cid: The cache ID of the data to store.
mixed $data: The data to store in the cache.
int $expire: One of the following values:
array $tags: An array of tags to be stored with the cache item. These should normally identify objects used to build the cache item, which should trigger cache invalidation when updated. For example if a cached item represents a node, both the node ID and the author's user ID might be passed in as tags. For example array('node' => array(123), 'user' => array(92)).
Drupal\Core\Cache\CacheBackendInterface::get()
Drupal\Core\Cache\CacheBackendInterface::getMultiple()
public function set($cid, $data, $expire = CacheBackendInterface::CACHE_PERMANENT, array $tags = array());