code: def ServicesSetMetod (self, sensor_id, service_id, method, parameters):
          
          if self.__SenseApiCall__('/sensors/{0}/services/{1}/{2}.json'.format(sensor_id, service_id, method), 'POST', parameters = parameters):
              return True
          else:
              self.__error__ = "api call unsuccessful"
              return False
docs: Set expression for the math service.
              
              @param sensor_id (int) - Sensor id of the sensor the service is connected to.
              @param service_id (int) - Service id of the service for which to set the expression.
              @param method (string) - The set method name.
              @param parameters (dictonary) - Parameters to set the expression of the math service.
                                      
              @return (bool) - Boolean indicating whether ServicesSetMethod was successful.