public static function get(array $nested, $key, $delimiter='.')
    {

        if (is_null($key)) return $nested;

        if (isset($nested[$key])) return $nested[$key];

        foreach (explode($delimiter, $key) as $segment) {
            if ( ! is_array($nested) || ! array_key_exists($segment, $nested))
            {
                return;
            }

            $nested = $nested[$segment];
        }

        return $nested;
    }