code: def list_commands(self, ctx):
          
          rv = defaults.list_commands(ctx)
          if self._commands_dir:
              for filename in os.listdir(self._commands_dir):
                  if _is_command_file(filename) and filename[:-3] not in rv:
                      rv.append(filename[:-3])
              rv.sort()
          return rv
docs: List commands from the commands dir and default group