'Initialize the sensor.'

def __init__(self, sensor_type, device_name, device):

    self._device_name = device_name
    self._name = '{}    {}'.format(device_name, SENSOR_TYPES[sensor_type][0])
    self._device = device
    self.type = sensor_type
    self._state = None
    self._unit_of_measurement = SENSOR_TYPES[sensor_type][1]
