Axis.setTitle((AxisTitle) null) can't remove the title

Steps to Reproduce

<zk>
    <charts id="chart" />
    <zscript>
    chart.getYAxis().setTitle((AxisTitle) null);
    </zscript>
</zk>

Current Result

The title of the Y-axis is still there.

Expected Result

The title of the Y-axis is hidden.

Debug Information

Method setTitle will compare null with the default value (null).
And the value won't be applied if not changed.

Workaround

call Axis.setTitle((String) null)