def test_dataset_method():
    ds = xray.Dataset({'boolV': boolV, 'intV': intV, 'stringV': stringV, 'multiV': multiV}, attrs=attrs)
    ds_interp = xray.Dataset({'boolV': boolV_interp, 'intV': intV_interp_lastseen, 'stringV': stringV_interp, 'multiV': multiV_interp}, attrs=attrs)
    assert xinterp.interp1d_Dataset(ds, method={'intV': 'lastseen'}, time=interp_time).identical(ds_interp)