code: def get_sensor(self, sensor_name):
          
          sensor = self._sensors.get(sensor_name, None)
          if not sensor:
              raise ValueError("Unknown sensor '%s'." % (sensor_name,))
          return sensor
docs: Fetch the sensor with the given name.
  
          Parameters
          ----------
          sensor_name : str
              Name of the sensor to retrieve.
  
          Returns
          -------
          sensor : Sensor object
              The sensor with the given name.