docs: def extend(self, cli_api, command_prefix="", sub_command="", **kwargs):
          """Extends this CLI api with the commands present in the provided cli_api object"""
          if sub_command and command_prefix:
              raise ValueError('It is not currently supported to provide both a command_prefix and sub_command')
  
          if sub_command:
              self.commands[sub_command] = cli_api
          else:
              for name, command in cli_api.commands.items():
                  self.commands["{}{}".format(command_prefix, name)] = command