public static function array_prepend( $array, $string, $deep = false )
    {
        if ( empty( $array ) || empty( $string ) )
        {
            return $array;
        }

        foreach ( $array as $key => $element )
        {
            if ( is_array( $element ) )
            {
                if ( $deep )
                {
                    $array[$key] = self::array_prepend( $element, $string, $deep );
                }
                else
                {
                    trigger_error( 'array_prepend: array element', E_USER_WARNING );
                }
            }
            else
            {
                $array[$key] = $string . $element;
            }
        }

        return $array;
    }