public static function purge_by_definition($component, $area, array $identifiers = array()) {
        // Create the cache.
        $cache = cache::make($component, $area, $identifiers);
        // Initialise, in case of a store.
        if ($cache instanceof cache_store) {
            $factory = cache_factory::instance();
            $definition = $factory->create_definition($component, $area, null);
            $cacheddefinition = clone $definition;
            $cacheddefinition->set_identifiers($identifiers);
            $cache->initialise($cacheddefinition);
        }
        // Purge baby, purge.
        $cache->purge();
        return true;
    }