Return list of titles parsed from HTML.

    Args:
        index_page (str): HTML content of the page you wish to analyze.

    Returns:
        list: List of :class:`.SourceString` objects.

def get_html_titles(index_page):
    """
    Return list of titles parsed from HTML.

    Args:
        index_page (str): HTML content of the page you wish to analyze.

    Returns:
        list: List of :class:`.SourceString` objects.
    """
    dom = dhtmlparser.parseString(index_page)

    title_tags = dom.find("title")

    return [
        SourceString(tag.getContent().strip(), "HTML")
        for tag in title_tags
        if tag.getContent().strip()
    ]