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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 serve(self, app, conf):
 """ A very simple approach for a WSGI server. """


        if self.args.reload:
            try:
                self.watch_and_spawn(conf)
            except ImportError:
                print('The `--reload` option requires `watchdog` to be '
                      'installed.')
                print('   $ pip install watchdog')
        else:
            self._serve(app, conf)