Parse authors of the book.

    Args:
        html_chunk (obj): HTMLElement containing slice of the page with details.

    Returns:
        list: List of :class:`structures.Author` objects. Blank if no author \
              found.

def _parse_authors(html_chunk):
    """
    Parse authors of the book.

    Args:
        html_chunk (obj): HTMLElement containing slice of the page with details.

    Returns:
        list: List of :class:`structures.Author` objects. Blank if no author \
              found.
    """
    authors = html_chunk.match(
        ["div", {"class": "comment"}],
        "h3",
        "a",
    )

    if not authors:
        return []

    authors = map(
        lambda x: Author(                            # create Author objects
            x.getContent().strip(),
            normalize_url(BASE_URL, x.params.get("href", None))
        ),
        authors
    )

    return filter(lambda x: x.name.strip(), authors)