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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 reset(self):
 """Reset a task. Allows a task to be started again, clears the ``return_values``. Raises: RuntimeError: If the task has not been stopped. """

        if self._status is not TaskStatus.STOPPED:
            raise RuntimeError("Cannot reset %s in state %s" %
                               (self, self._status))
        self._reset()
        self.return_values = {}
        self._status = TaskStatus.IDLE