def test_view_failed_delitem(attr):
    adata = gen_adata((10, 10))
    view = adata[5:7, :][:, :5]
    adata_hash = joblib.hash(adata)
    view_hash = joblib.hash(view)

    with pytest.raises(KeyError):
        getattr(view, attr).__delitem__("not a key")

    assert view.is_view
    assert adata_hash == joblib.hash(adata)
    assert view_hash == joblib.hash(view)
def trapped_signals(cls, new_signal_handler):
        """A contextmanager which temporarily overrides signal handling.

        NB: This method calls signal.signal(), which will crash if not called from the main thread!
        """
        previous_signal_handler = cls.reset_signal_handler(new_signal_handler)
        try:
            yield
        finally:
            cls.reset_signal_handler(previous_signal_handler)