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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 _effective_view_filter(self):
 """Returns the mongodb relationship filter for effective views"""

        if self._effective_view == EFFECTIVE:
            now = datetime.datetime.utcnow()
            return {'startDate': {'$$lte': now}, 'endDate': {'$$gte': now}}
        return {}