tabSelected() {
        const sheetViewNode = this._getOrCreateSheetViewNode();
        return new ArgHandler('Sheet.tabSelected')
            .case(() => {
                return sheetViewNode.attributes.tabSelected === 1;
            })
            .case('boolean', selected => {
                if (selected) sheetViewNode.attributes.tabSelected = 1;
                else delete sheetViewNode.attributes.tabSelected;
                return this;
            })
            .handle(arguments);
    }
Sets whether this sheet is selected.
@param {boolean} selected - True to select, false to deselected.
@returns {Sheet} The sheet.