'Initialize the sensor.'

def __init__(self, vasttrafik, planner, name, departure, heading, delay):

    self._vasttrafik = vasttrafik
    self._planner = planner
    self._name = (name or departure)
    self._departure = planner.location_name(departure)[0]
    self._heading = (planner.location_name(heading)[0] if heading else None)
    self._delay = timedelta(minutes=delay)
    self._departureboard = None
