@Override
    public boolean isRegistered(JobID jobId) {
        return jobManagerRunners.containsKey(jobId);
    }
@Test
    void testIsRegistered() {
        final JobID jobId = new JobID();
        testInstance.register(TestingJobManagerRunner.newBuilder().setJobId(jobId).build());
        assertThat(testInstance.isRegistered(jobId)).isTrue();
    }