getTab = el => {
    while (el) {
      if (isTabDiv(el)) {
        return el;
      }
      el = el.parentElement;
    }
    return false;
  }
Fired when a tab is selected.

@event sap.ui.webc.main.TabContainer#tab-select
@param {HTMLElement} tab The selected <code>tab</code>.
@param {Integer} tabIndex The selected <code>tab</code> index in the flattened array of all tabs and their subTabs, provided by the <code>allItems</code> getter.
@public
@allowPreventDefault