def METHOD_NAME(rss_feed_content, blog_url, element):
    """
    The items in the feed need to have valid urls in link and guid.
    As stated by W3 FEED Validator:
    * "link must be a full and valid URL"
    * "guid must be a full URL, unless isPermaLink attribute is false: /weblog/posts/the-minimal-server.html"
    """
    # This validation regex is taken from django.core.validators
    url_validation_regex = re.compile(
        r"^(?:http|ftp)s?://"  # http:// or https://
        # domain...
        r"(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|"
        r"localhost|"  # localhost...
        # ...or ipv4
        r"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}|"
        # ...or ipv6
        r"\[?[A-F0-9]*:[A-F0-9:]+\]?)" r"(?::\d+)?" r"(?:/?|[/?]\S+)$",  # optional port
        re.IGNORECASE,
    )
    def is_valid_URL(url):
        return url_validation_regex.match(url) is not None
    et = etree.parse(StringIO(rss_feed_content))
    channel = et.find("channel")
    item = channel.find("item")
    element = item.find(element)
    assert is_valid_URL(element.text)
    assert blog_url in element.text