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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def absolute_urls(html):
 """ Converts relative URLs into absolute URLs. Used for RSS feeds to provide more complete HTML for item descriptions, but could also be used as a general richtext filter. """


    from bs4 import BeautifulSoup
    from yacms.core.request import current_request

    request = current_request()
    if request is not None:
        dom = BeautifulSoup(html, "html.parser")
        for tag, attr in ABSOLUTE_URL_TAGS.items():
            for node in dom.findAll(tag):
                url = node.get(attr, "")
                if url:
                    node[attr] = request.build_absolute_uri(url)
        html = str(dom)
    return html