PHP function/class that formats/indents my HTML code? [duplicate]

Question

Is there a PHP function/class that cleans my HTML code?

For example:

$html = "<ul><li>item1</li><li>item2</li>";
echo htmlClean($html);

/*
    Outputs:
    <ul>
        <li>item1</li>
        <li>item2</li>
    </ul>
*/