code: def assert_no_leftovers(self):
      
      leftovers = []
      for name in self._members.keys():
        if name in self._members and name not in self._documented:
          leftovers.append(name)
      if leftovers:
        raise RuntimeError("%s: undocumented members: %s" %
                           (self._title, ", ".join(leftovers)))
docs: Generate an error if there are leftover members.