assertNull(ReverseTreeRepositoryListener.lookupCollectStepData(doesNotHaveIt));

        final CollectStepData data = mock(CollectStepData.class);

        RequestTrace haveItFirst = RequestTrace.newChild(null, data)
                .newChild("foo")
                .newChild("bar")
                .newChild("baz");
        assertSame(data, ReverseTreeRepositoryListener.lookupCollectStepData(haveItFirst));