protected function parseAllocationStats($str)
    {
        $stats = array();

        foreach (explode(',', $str) as $kv) {
            @list($size, $objects, $extra) = explode('=', $kv);

            // hack to prevent incorrect values when parsing the >=256 key
            if (isset($extra)) {
                $size = ">=$objects";
                $objects = $extra;
            }

            $stats[$size] = $objects;
        }

        return $stats;
    }