src/vs/workbench/browser/parts/editor/tabsTitleControl.ts/TabsTitleControl/doWithTab
class TabsTitleControl:	private doWithTab(index: number, editor: IEditorInput, fn: (editor: IEditorInput, index: number, tabContainer: HTMLElement, tabLabelWidget: IResourceLabel, tabLabel: IEditorInputLabel, tabActionBar: ActionBar) => void): void {
		const tabsContainer = assertIsDefined(this.tabsContainer);
		const tabContainer = tabsContainer.children[index] as HTMLElement;
		const tabResourceLabel = this.tabResourceLabels.get(index);
		const tabLabel = this.tabLabels[index];
		const tabActionBar = this.tabActionBars[index];
		if (tabContainer && tabResourceLabel && tabLabel) {
			fn(editor, index, tabContainer, tabResourceLabel, tabLabel, tabActionBar);
		}
	}