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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 name_inner_event(cls):
 """Decorator to rename cls.Event 'Event' as 'cls.Event'"""

    if hasattr(cls, 'Event'):
        cls.Event._event_name = '{}.Event'.format(cls.__name__)
    else:
        warnings.warn('Class {} does not have a inner Event'.format(cls))
    return cls