def get_source_coords(st):
    """
    Get the coordinates of the source object.
    Only works for SU format currently


    :type st: obspy.core.stream.Stream
    :param st: a stream to query for coordinates
    :rtype s_coords: tuple of lists
    :return s_coords: list of source coordinates, matching the order in `st`
        ([sx], [sy], [sz])
    """
    if hasattr(st[0].stats, "su"):
        sx, sy, sz = [], [], []
        for tr in st:
            sx += [tr.stats.su.trace_header.source_coordinate_x]
            sy += [tr.stats.su.trace_header.source_coordinate_y]
            sz += [0.]
        return sx, sy, sz
    else:
        raise NotImplementedError