docs: def is_archive(self):
          """ Given a parsed feed, returns True if this is an archive feed """
  
          ns_prefix = self.archive_namespace
          if ns_prefix:
              if ns_prefix + '_archive' in self.feed.feed:
                  # This is declared to be an archive view
                  return True
              if ns_prefix + '_current' in self.feed.feed:
                  # This is declared to be the current view
                  return False
  
          # Either we don't have the namespace, or the view wasn't declared.
          rels = collections.defaultdict(list)
          for link in self.feed.feed.links:
              rels[link.rel].append(link.href)
  
          return ('current' in rels and
                  ('self' not in rels or
                   rels['self'] != rels['current']))