@Test
    public void testTaskToDomainOverrides() {
        WorkflowModel workflow = generateSampleWorkflow();
        List<TaskModel> tasks = generateSampleTasks(4);

        Map<String, String> taskToDomain = new HashMap<>();
        taskToDomain.put("*", "mydomain");
        taskToDomain.put("task2", "someInactiveDomain, NO_DOMAIN");
        taskToDomain.put("task3", "someActiveDomain, NO_DOMAIN");
        taskToDomain.put("task4", "someInactiveDomain, someInactiveDomain2");
        workflow.setTaskToDomain(taskToDomain);

        PollData pollData1 =
                new PollData(
                        "queue1", "mydomain", "worker1", System.currentTimeMillis() - 99 * 100);
        PollData pollData2 =
                new PollData(
                        "queue2",
                        "someActiveDomain",
                        "worker2",
                        System.currentTimeMillis() - 99 * 100);
        when(executionDAOFacade.getTaskPollDataByDomain(anyString(), eq("mydomain")))
                .thenReturn(pollData1);
        when(executionDAOFacade.getTaskPollDataByDomain(anyString(), eq("someInactiveDomain")))
                .thenReturn(null);
        when(executionDAOFacade.getTaskPollDataByDomain(anyString(), eq("someActiveDomain")))
                .thenReturn(pollData2);
        when(executionDAOFacade.getTaskPollDataByDomain(anyString(), eq("someInactiveDomain")))
                .thenReturn(null);
        workflowExecutor.setTaskDomains(tasks, workflow);

        assertEquals("mydomain", tasks.get(0).getDomain());
        assertNull(tasks.get(1).getDomain());
        assertEquals("someActiveDomain", tasks.get(2).getDomain());
        assertEquals("someInactiveDomain2", tasks.get(3).getDomain());
    }
Simulate Queue push failures and assert that scheduleTask doesn't throw an exception.
core/src/test/java/com/netflix/conductor/core/execution/TestWorkflowExecutor.java