List<OrderEnumerationHandler> (@NotNull Module module) { List<OrderEnumerationHandler> customHandlers = null; for (OrderEnumerationHandler.Factory handlerFactory : OrderEnumerationHandler.EP_NAME.getExtensionList()) { if (handlerFactory.isApplicable(module)) { if (customHandlers == null) { customHandlers = new SmartList<>(); } customHandlers.add(handlerFactory.createHandler(module)); } } return customHandlers == null ? Collections.emptyList() : customHandlers; }