def METHOD_NAME(cls):
    cls.parf = os.path.join(datadir, "B1855+09_NANOGrav_dfg+12_DMX.par")
    cls.timf = os.path.join(datadir, "B1855+09_NANOGrav_dfg+12.tim")
    cls.DMXm = mb.get_model(cls.parf)
    cls.toas = toa.get_TOAs(cls.timf, ephem="DE405", include_bipm=False)