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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 _run_driver(self, item_session: ItemSession, request, response):
        '''Start PhantomJS processing.'''
        _logger.debug('Started PhantomJS processing.')

        session = PhantomJSCoprocessorSession(
            self._phantomjs_driver_factory, self._root_path,
            self._processing_rule, self._file_writer_session,
            request, response,
            item_session, self._phantomjs_params, self._warc_recorder
        )

        with contextlib.closing(session):
            yield from session.run()

        _logger.debug('Ended PhantomJS processing.')