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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 refresh(self):
        '''
        Refresh the document from the database.
        '''
        d = self.rr.table(self.table).get(self.pk_value).run()
        if d is None:
            raise KeyError
        for k in d:
            dict.__setitem__(
                    self, k, watch(d[k], callback=self._updated, field=k))