Adding styleClass to a SegmentedButtonItem

Hello,

i do have the following situation, i do have the following row(see the Image below), with three Controlls:

1. Label

2. Text

3. SegmentedButton with two SegmentedButtonItems Items: One, Two

- When getting the Items

this.byId("tableName").getItems()[rowIndex].mAggregations.cells

I do get three Elements, aformentioned three Controlls, when adding a StyleClass by:

this.byId("tableName").getItems()[rowIndex].mAggregations.cells[0].addStyleClass("styleClass")

The corresponding Controll recieves the style propreties.

Issue: However when, trying to apply style propreties, to for example: One-Button, aformentioned .addStyleClass stops working.

Question: How to make .addStyleClass work for one of the SegmentedButtonItems ?