code: def add_argument(self, *args, **kwargs):
          
  
          if len(args) == 1 and isinstance(args[0], self.argument_class):
              self.args.append(args[0])
          else:
              self.args.append(self.argument_class(*args, **kwargs))
  
          # Do not know what other argument classes are out there
          if self.trim and self.argument_class is Argument:
              # enable trim for appended element
              self.args[-1].trim = kwargs.get('trim', self.trim)
  
          return self
docs: Adds an argument to be parsed.
  
          Accepts either a single instance of Argument or arguments to be passed
          into :class:`Argument`'s constructor.
  
          See :class:`Argument`'s constructor for documentation on the
          available options.