def trackNamespace(self, prefix, uri):
        loweruri = uri.lower()
        if not self.version:
            if (prefix, loweruri) == (None, 'http://my.netscape.com/rdf/simple/0.9/'):
                self.version = 'rss090'
            elif loweruri == 'http://purl.org/rss/1.0/':
                self.version = 'rss10'
            elif loweruri == 'http://www.w3.org/2005/atom':
                self.version = 'atom10'
        if loweruri.find('backend.userland.com/rss') != -1:
            # match any backend.userland.com namespace
            uri = 'http://backend.userland.com/rss'
            loweruri = uri
        if loweruri in self._matchnamespaces:
            self.namespacemap[prefix] = self._matchnamespaces[loweruri]
            self.namespacesInUse[self._matchnamespaces[loweruri]] = uri
        else:
            self.namespacesInUse[prefix or ''] = uri
dataset/ETHPy150Open SickRage/SickRage/lib/feedparser/mixin.py/_FeedParserMixin.trackNamespace/original