Crunz\Configuration\Configuration::set PHP Method

    public function set($key, $value)
    {
        if (is_null($key)) {
            return $array = $value;
        }
        $keys = explode('.', $key);
        while (count($keys) > 1) {
            $key = array_shift($keys);
            // If the key doesn't exist at this depth, we will just create an empty array
            // to hold the next value, allowing us to create the arrays to hold final
            // values at the correct depth. Then we'll keep digging into the array.
            if (!isset($array[$key]) || !is_array($array[$key])) {
                $array[$key] = [];
            }
            $array =& $array[$key];
        }
        $array[array_shift($keys)] = $value;
        return $array;
    }