Filter via header row in TreeList

I'm using the 2015.01 Kendo Javascript UI. In the documentation, (http://docs.telerik.com/kendo-ui/api/javascript/ui/treelist#configuration-columns.filterable.ui), it says that you can do the following, but I tried and it doesn't work.

filterable: {
ui: function(element) {
element.kendoDateTimePicker(); // initialize a Kendo UI DateTimePicker
}

OR

filterable: {
ui: "datetimepicker"
}

For the first example, I tried to put the following as the callback function just to see if it was ever called, and it wasn't.

function(element){ alert("efeaseaij"); }