def METHOD_NAME():
    cat_index, finder_id, ntot, mvir = stat.AHFStatFile(ts3.filename).read("npart","Mvir")
    assert all(cat_index==[1,2,3,4])
    assert all(finder_id==[32425324, 8712365, 3478612, 907234568])
    assert all(ntot==[5900575,506026,498433,226976])
    npt.assert_almost_equal(mvir,   [5.02432e+11,4.67419e+10, 4.87598e+10, 2.23568e+10  ], decimal=5)