Map<MetricName, Metric> producerMetrics() {
        return activeTaskCreator.producerMetrics();
    }
@Test
    public void shouldTransmitProducerMetrics() {
        final MetricName testMetricName = new MetricName("test_metric", "", "", new HashMap<>());
        final Metric testMetric = new KafkaMetric(
            new Object(),
            testMetricName,
            (Measurable) (config, now) -> 0,
            null,
            new MockTime());
        final Map<MetricName, Metric> dummyProducerMetrics = singletonMap(testMetricName, testMetric);

        when(activeTaskCreator.producerMetrics()).thenReturn(dummyProducerMetrics);

        assertThat(taskManager.producerMetrics(), is(dummyProducerMetrics));
    }