Pinq\Caching\ArrayAccessCacheAdapter::doClear PHP Method

    public function doClear($namespace = null)
    {
        if ($this->arrayAccess instanceof \Traversable) {
            $keys = array_keys(iterator_to_array($this->arrayAccess, true));
            foreach ($keys as $key) {
                if ($namespace === null || strpos($key, $namespace) === 0) {
                    unset($this->arrayAccess[$key]);
                }
            }
        } else {
            throw new PinqException('Cannot clear cache %s: does not support clearing', get_class($this->arrayAccess));
        }
    }