def test_set_var(adata, subset_func):
    init_hash = joblib.hash(adata)

    subset = adata[:, subset_func(adata.var_names)]

    new_var = pd.DataFrame(
        dict(a=np.ones(subset.n_vars), b=np.ones(subset.n_vars)),
        index=subset.var_names,
    )

    assert subset.is_view
    subset.var = new_var
    assert not subset.is_view
    assert np.all(subset.var == new_var)

    assert joblib.hash(adata) == init_hash
def exiter_as_until_exception(
        cls, new_exiter_fun: Callable[[Optional[Exiter]], Exiter]
    ) -> Iterator[None]:
        """Temporarily override the global exiter, except this will unset it when an exception
        happens."""
        previous_exiter = cls._exiter
        new_exiter = new_exiter_fun(previous_exiter)
        try:
            cls._reset_exiter(new_exiter)
            yield
        finally:
            cls._reset_exiter(previous_exiter)