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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 create_payload(self):
 """Convert ``sync_date`` to a string. The ``sync_date`` instance attribute on the current object is not affected. However, the ``'sync_date'`` key in the dict returned by ``create_payload`` is a string. """

        data = super(SyncPlan, self).create_payload()
        if isinstance(data.get('sync_date'), datetime):
            data['sync_date'] = data['sync_date'].strftime('%Y-%m-%d %H:%M:%S')
        return data