Returns the appropriate parser to use for adding arguments to your command.

def parser(self):
        """Returns the appropriate parser to use for adding arguments to your command."""
        if self._command_parser is None:
            parents = []
            if self.need_verbose:
                parents.append(_verbose_parser)
            if self.need_settings:
                parents.append(_settings_parser)

            self._command_parser = self._main_parser.add_parser(self.name,
                                                                help=self.help,
                                                                parents=parents,
                                                                formatter_class=argparse.RawDescriptionHelpFormatter)
        return self._command_parser