jSpreadsheet CE custom tooltip on hover

Question

I am trying to set up custom tooltips for column headers. While the pro vers. site describes how to do this, I could not find the information on the CE site. I tried the following, but the column title appears in the tooltip.

jspreadsheet(document.getElementById('spreadsheet'), {
    data: [ 'Test' ],
    columns: [
        {
            type: 'text',
            title: 'MyTitle',
            tooltip: 'This is a custom tooltip',
            width: 160
        }
    ]
});