@Test
public void testBatchAttributesStamped() {

  when(batchingDescriptor.countElements(anyString())).thenReturn(10L);
  when(batchingDescriptor.countBytes(anyString())).thenReturn(20L);
  tracedBatchingCallable.futureCall("test", callContext);
  verify(tracer).batchRequestSent(10, 20);
}