'Yields all links with the given relations'

def explicit_rel_links(self, rels=('homepage', 'download')):

    rels = set(rels)
    for anchor in self.parsed.findall('.//a'):
        if (anchor.get('rel') and anchor.get('href')):
            found_rels = set(anchor.get('rel').split())
            if (found_rels & rels):
                href = anchor.get('href')
                url = self.clean_link(urlparse.urljoin(self.base_url, href))
                (yield Link(url, self, trusted=False))
