src/vs/workbench/services/history/browser/historyService.ts/HistoryService/openPreviouslyUsedEditor
class HistoryService:	openPreviouslyUsedEditor(groupId?: GroupIdentifier): Promise<void> {
		const [stack, index] = this.ensureRecentlyUsedStack(index => index + 1, groupId);

		return this.doNavigateInRecentlyUsedEditorsStack(stack[index], groupId);
	}