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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_and_update(self):
 """Refresh the operation and update the result if needed."""

        # If the currently cached operation is done, no need to make another
        # RPC as it will not change once done.
        if not self._operation.done:
            self._operation = self._refresh()
            self._set_result_from_operation()