code: def add_settings_parser(subparsers, parent_parser):
      
      # The following parser is for the settings subsection of commands.  These
      # commands display information about the currently applied on-chain
      # settings.
  
      settings_parser = subparsers.add_parser(
          'settings',
          help='Displays on-chain settings',
          description='Displays the values of currently active on-chain '
                      'settings.')
  
      settings_parsers = settings_parser.add_subparsers(
          title='settings',
          dest='settings_cmd')
      settings_parsers.required = True
  
      list_parser = settings_parsers.add_parser(
          'list',
          help='Lists the current keys and values of on-chain settings',
          description='List the current keys and values of on-chain '
                      'settings. The content can be exported to various '
                      'formats for external consumption.'
      )
  
      list_parser.add_argument(
          '--url',
          type=str,
          help="identify the URL of a validator's REST API",
          default='http://localhost:8008')
  
      list_parser.add_argument(
          '--filter',
          type=str,
          default='',
          help='filters keys that begin with this value')
  
      list_parser.add_argument(
          '--format',
          default='default',
          choices=['default', 'csv', 'json', 'yaml'],
          help='choose the output format')
docs: Creates the args parser needed for the settings command and its
      subcommands.