### Question:
AbstractHttpAccessAuditFilter implements Filter { protected String getUserIdForAccessOutcome(Response response) { String userId = AuditRequestContext.getProperty(AuditConstants.USER_ID); return userId == null ? "" : userId; } AbstractHttpAccessAuditFilter(Component component,
            AuditEventPublisher auditEventPublisher, AuditEventFactory auditEventFactory); @Override Promise<Response, NeverThrowsException> filter(final Context context, final Request request, Handler next);  }### Answer:
@Test public void shouldGetUserIdForAccessOutcomeIfNotSet() { Response response = new Response(); AuditRequestContext.putProperty(USER_ID, null); String userId = auditFilter.getUserIdForAccessOutcome(response); assertThat(userId).isEmpty(); }