@VisibleForTesting
    List<MessageSummary> getMessageBacklog(EventNotificationContext ctx, TeamsEventNotificationConfigV2 config) {
        List<MessageSummary> backlog = notificationCallbackService.getBacklogForEvent(ctx);
        if (config.backlogSize() > 0 && backlog != null) {
            return backlog.stream().limit(config.backlogSize()).collect(Collectors.toList());
        }
        return backlog;
    }
@Test
    public void testBacklogMessageLimitWhenBacklogSizeIsZero() {
        TeamsEventNotificationConfigV2 config = TeamsEventNotificationConfigV2.builder()
                .backlogSize(0)
                .build();

        // Global setting is at 50 and the message override is 0 then the backlog size = 50
        List<MessageSummary> messageSummaries = teamsEventNotification.getMessageBacklog(eventNotificationContext, config);
        assertThat(messageSummaries.size()).isEqualTo(50);
    }