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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 SensorMetatagsGet(self, sensor_id, namespace = None):

 """
 Retrieve the metatags of a sensor.
 
 @param sensor_id (int) - Id of the sensor to retrieve metatags from
 @param namespace (stirng) - Namespace for which to retrieve metatags.
 
 @return (bool) - Boolean indicating whether SensorMetatagsGet was successful
 """

        ns = "default" if namespace is None else namespace
        if self.__SenseApiCall__('/sensors/{0}/metatags.json'.format(sensor_id), 'GET', parameters = {'namespace': ns}):
            return True
        else:
            self.__error__ = "api call unsuccessful"
            return False