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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _register_opt(parser, *args, **kwargs):
 """ Handler to register an option for both Flake8 3.x and 2.x. This is based on: https://github.com/PyCQA/flake8/blob/3.0.0b2/docs/source/plugin-development/cross-compatibility.rst#option-handling-on-flake8-2-and-3 It only supports `parse_from_config` from the original function and it uses the `Option` object returned to get the string. """

        try:
            # Flake8 3.x registration
            parser.add_option(*args, **kwargs)
        except (optparse.OptionError, TypeError):
            # Flake8 2.x registration
            parse_from_config = kwargs.pop('parse_from_config', False)
            option = parser.add_option(*args, **kwargs)
            if parse_from_config:
                parser.config_options.append(option.get_opt_string().lstrip('-'))