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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 set_value(self, value, status=NOMINAL, timestamp=None, major=DEFAULT_KATCP_MAJOR):
 """Check and then set the value of the sensor. Parameters value : object Value of the appropriate type for the sensor. status : Sensor status constant Whether the value represents an error condition or not. timestamp : float in seconds or None The time at which the sensor value was determined. Uses current time if None. major : int Major version of KATCP to use when interpreting types. Defaults to latest implemented KATCP version. """

        self._kattype.check(value, major)
        if timestamp is None:
            timestamp = time.time()
        self.set(timestamp, status, value)