def __init__(self, station, elev=0):
        """
        Args:
            station (TopocentricFrame): Station from which to listen to elevation events
            elev (float): Elevation from which to trigger the listener (in radians)
        """
        self.station = station
        self.elev = elev
def __init__ ( self , station , elev = 0 ) : self . station = station self . elev = elev
Args:
            station (TopocentricFrame): Station from which to listen to elevation events
            elev (float): Elevation from which to trigger the listener (in radians)