code: def _get_help_names(self):
          
          # Determine the additional help topics, if any.
          help_names = {}
          token2cmdname = self._get_canonical_map()
          for attrname, attr in self._gen_names_and_attrs():
              if not attrname.startswith("help_"): continue
              help_name = attrname[5:]
              if help_name not in token2cmdname:
                  help_names[help_name] = attr
          return help_names
docs: Return a mapping of help topic name to `.help_*()` method.