@Test
public void testExplicitParent() {

  OpencensusTracerFactory factory =
      new OpencensusTracerFactory(internalTracer, defaultSpanAttributes);
  Span parentSpan = mock(Span.class);
  OpencensusTracer parentTracer =
      new OpencensusTracer(internalTracer, parentSpan, OperationType.Unary);
  factory.newTracer(parentTracer, SpanName.of("FakeClient", "FakeMethod"), OperationType.Unary);
  verify(internalTracer).spanBuilderWithExplicitParent(anyString(), same(parentSpan));
}