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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 make_event_data(self, flavor, data):
 """ Marshall ``flavor`` and ``data`` into a standard event. """

        if not flavor.startswith('_'):
            raise ValueError('Event flavor must start with _underscore')

        d = {'source': {'space': self._event_space, 'id': self._source_id}}
        d.update(data)
        return {flavor: d}