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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 populate_audit_fields(self, event):
 """Populates the the audit JSON fields with raw data from the model, so all changes can be tracked and diffed. Args: event (Event):
 The Event instance to attach the data to instance (fleaker.db.Model):
 The newly created/updated model """

        event.updated = self._data
        event.original = self.get_original()._data