def test_coord_with_interval_step_x_and_y_raises_valueeerror(self) -> None:
        """Test that step plot with intervals both on x and y axes raises an error."""
        arr = xr.DataArray(
            [pd.Interval(0, 1), pd.Interval(1, 2)],
            coords=[("x", [pd.Interval(0, 1), pd.Interval(1, 2)])],
        )
        with pytest.raises(TypeError, match="intervals against intervals"):
            arr.plot.step()
Test that step plot with intervals both on x and y axes raises an error.
xarray/tests/test_plot.py