code: def add_argument(self, parser, bootstrap=False):
          
          if self.cli_expose:
              for child in self.children.values():
                  child.add_argument(parser, bootstrap)
docs: Add dict-style item as an argument to the given parser.
  
          The dict item will take all the nested items in the dictionary and
          namespace them with the dict name, adding each child item as
          their own CLI argument.
  
          Examples:
              A non-nested dict item with the name 'db' and children named
              'port' and 'host' will result in the following being valid
              CLI args:
  
              ['--db-host', 'localhost', '--db-port', '1234']
  
          Args:
              parser (argparse.ArgumentParser): The parser to add this item to.
              bootstrap (bool): Flag to indicate whether you only want to mark
                  this item as required or not.