code: def add_arguments(self, parser):
          
          subparsers = parser.add_subparsers(help='sub-command help',
                                             dest='command')
  
          add_parser = partial(_add_subparser, subparsers, parser)
  
          add_parser('list', help="list concurrency triggers")
          add_parser('drop', help="drop  concurrency triggers")
          add_parser('create', help="create concurrency triggers")
  
          parser.add_argument('-d', '--database',
                              action='store',
                              dest='database',
                              default=None,
                              help='limit to this database')
  
          parser.add_argument('-t', '--trigger',
                              action='store',
                              dest='trigger',
                              default=None,
                              help='limit to this trigger name')
docs: Entry point for subclassed commands to add custom arguments.