code: def _add_sub_parsers(self, top_level_parser, methods_to_parse, class_name):
          
          description = "Accessible methods of {}".format(class_name)
          sub_parsers = top_level_parser.add_subparsers(description=description,
                                                        dest="method")
          # Holds the mapping between the name registered for the parser
          # and the method real name. It is useful in the 'inner_call'
          # method retrieve the real method
          parser_to_method = {}
          for method_name, parser in methods_to_parse.items():
              # We use the name provided in 'create_parser` or the name of the
              # decorated method
              parser_name = parser.get_name() or method_name
              # Make the method name compatible for the argument parsing
              if parser_name.startswith("_"):
                  if not self._parse_private:
                      # We skip private methods if the caller asked not to
                      # parse them
                      continue
                  # 'Private' methods are exposed without their leading or
                  # trailing '_'s. Also works for 'special' methods.
                  parser_name = parser_name.strip("_")
              parser_name = parser_name.replace("_", "-")
              parser_to_method[parser_name] = method_name
              sub_parsers.add_parser(parser_name, parents=[parser],
                                     add_help=False,
                                     description=parser.description)
          return parser_to_method
docs: Add all the sub-parsers to the top_level_parser.
  
          Args:
              top_level_parser: the top level parser
              methods_to_parse: dict of method name pointing to their associated
              argument parser
              class_name: name of the decorated class
  
          Returns:
              a dict of registered name of the parser i.e. sub command name
              pointing to the method real name