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_tags = html_chunk.match(
        ["div", {"class": "polozka_autor"}],
        "a"
    )

    authors = []
    for author_tag in authors_tags:
        # get name
        name = author_tag.getContent().strip()

        # skip tags without name
        if not name:
            continue

        # get url - if not found, set it to None
        url = author_tag.params.get("href", None)
        if url:
            url = normalize_url(BASE_URL, url)

        authors.append(
            Author(name, url)
        )

    return authors