Base::extend PHP Method

    function extend($key, $src, $keep = FALSE)
    {
        $ref =& $this->ref($key);
        if (!$ref) {
            $ref = [];
        }
        $out = array_replace_recursive(is_string($src) ? $this->hive[$src] : $src, $ref);
        if ($keep) {
            $ref = $out;
        }
        return $out;
    }