src/vs/workbench/browser/parts/editor/tabsTitleControl.ts/TabsTitleControl/forEachTab
class TabsTitleControl:	private forEachTab(fn: (editor: EditorInput, index: number, tabContainer: HTMLElement, tabLabelWidget: IResourceLabel, tabLabel: EditorInputLabel, tabActionBar: ActionBar) => void, fromIndex?: number, toIndex?: number): void {
		this.group.editors.forEach((editor, index) => {
			if (typeof fromIndex === 'number' && fromIndex > index) {
				return; // do nothing if we are not yet at `fromIndex`
			}

			if (typeof toIndex === 'number' && toIndex < index) {
				return; // do nothing if we are beyond `toIndex`
			}

			this.doWithTab(index, editor, fn);
		});
	}