@Test
public void testToString() {

  @SuppressWarnings("unchecked")
  BatchingDescriptor<Integer, Integer> batchingDescriptor =
      Mockito.mock(BatchingDescriptor.class);
  BatchingCallSettings.Builder<Integer, Integer> builder =
      BatchingCallSettings.newBuilder(batchingDescriptor);
  BatchingSettings batchingSettings =
      BatchingSettings.newBuilder().setElementCountThreshold(1L).build();
  FlowController flowController = Mockito.mock(FlowController.class);
  Set<StatusCode.Code> retryCodes = Sets.newHashSet(Code.UNAVAILABLE);
  RetrySettings retrySettings = RetrySettings.newBuilder().build();
  builder
      .setRetryableCodes(retryCodes)
      .setRetrySettings(retrySettings)
      .setBatchingSettings(batchingSettings)
      .setFlowController(flowController);
  Truth.assertThat(builder.build().toString()).contains("retryableCodes=" + retryCodes);
  Truth.assertThat(builder.build().toString()).contains("retrySettings=" + retrySettings);
  Truth.assertThat(builder.build().toString()).contains("batchingSettings=" + batchingSettings);
}