static function ltrim_position($content, $position, $br = true)
    {
        $blanks = array("\t", "\0", "\x0B", " ");

        if ($br) {
            $blanks[] = "\r";
            $blanks[] = "\n";
        }

        while (isset($content[$position]) && isset($content[$position + 1])
            && in_array($content[$position], $blanks, true)
        ) {
            $position++;
        }

        return $position;
    }