code: def subparsers(self):
          
          try:
              return self.__subparsers
          except AttributeError:
              parent = super(ArgumentParser, self)
              self.__subparsers = parent.add_subparsers(title="drill down")
              self.__subparsers.metavar = "COMMAND"
              return self.__subparsers
docs: Obtain the subparser's object.