ModelSource.ModelLocator locator = mock(ModelSource.ModelLocator.class);
        Path resolvedPath = Paths.get("/tmp/subproject/pom.xml");
        when(locator.locateExistingPom(any(Path.class))).thenReturn(resolvedPath);

        Sources.BuildPathSource source = (Sources.BuildPathSource) Sources.buildSource(basePath);
        ModelSource resolved = source.resolve(locator, "subproject");

        assertNotNull(resolved);

    TestHashSet<Entry<String>> entrySet = new TestHashSet<>();
    when((Comparator<Comparable<String>>) toCopy.comparator())
        .thenReturn(Ordering.<Comparable<String>>natural());
    when(toCopy.entrySet()).thenReturn(entrySet);
    ImmutableSortedMultiset<String> unused = ImmutableSortedMultiset.copyOfSorted(toCopy);
    assertTrue(entrySet.toArrayCalled);
  }