code: def add_argument(self, parser, bootstrap=False):
          
          tmp_default = self.default
          exclusive_grp = parser.add_mutually_exclusive_group()
          self.default = True
          args = self._get_argparse_names(parser.prefix_chars)
          kwargs = self._get_argparse_kwargs(bootstrap)
          exclusive_grp.add_argument(*args, **kwargs)
  
          self.default = False
          args = self._get_argparse_names(parser.prefix_chars)
          kwargs = self._get_argparse_kwargs(bootstrap)
          exclusive_grp.add_argument(*args, **kwargs)
  
          self.default = tmp_default
docs: Add boolean item as an argument to the given parser.
  
          An exclusive group is created on the parser, which will add
          a boolean-style command line argument to the parser.
  
          Examples:
              A non-nested boolean value with the name 'debug' will result
              in a command-line argument like the following:
  
              '--debug/--no-debug'
  
          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.