def METHOD_NAME(self):
    """
    Returns a list of available elevations for this layer.
    Assumes that the same elevation levels are available for all time
    steps.
    """
    logging.debug("checking vertical dimensions for layer '%s'.", self.name)
    if self.uses_elevation_dimension() and self.driver is not None:
        return [str(x) for x in self.driver.METHOD_NAME(self._vert_type)]
    else:
        return []