def html_to_pdf(content, encoding="utf-8",
                link_callback=fetch_resources, **kwargs):
    """
    Converts html ``content`` into PDF document.

    :param unicode content: html content
    :returns: PDF content
    :rtype: :class:`bytes`
    :raises: :exc:`~easy_pdf.exceptions.PDFRenderingError`
    """
    src = BytesIO(content.encode(encoding))
    dest = BytesIO()

    pdf = pisa.pisaDocument(src, dest, encoding=encoding,
                            link_callback=link_callback, **kwargs)
    if pdf.err:
        logger.error("Error rendering PDF document")
        for entry in pdf.log:
            if entry[0] == xhtml2pdf.default.PML_ERROR:
                logger_x2p.error("line %s, msg: %s, fragment: %s", entry[1], entry[2], entry[3])
        raise PDFRenderingError("Errors rendering PDF", content=content, log=pdf.log)

    if pdf.warn:
        for entry in pdf.log:
            if entry[0] == xhtml2pdf.default.PML_WARNING:
                logger_x2p.warning("line %s, msg: %s, fragment: %s", entry[1], entry[2], entry[3])

    return dest.getvalue()
Converts html ``content`` into PDF document.

    :param unicode content: html content
    :returns: PDF content
    :rtype: :class:`bytes`
    :raises: :exc:`~easy_pdf.exceptions.PDFRenderingError`