HasBoth hasBoth2 = new HasBoth();
    Iterable<TypeA> alist = Lists.newArrayList(hasBoth1, new TypeA(), hasBoth2, new TypeA());
    Iterable<TypeB> blist = filter(alist, TypeB.class);

    Iterator<TypeB> expectedIterator = Arrays.<TypeB>asList(hasBoth1, hasBoth2).iterator();
    blist.forEach(b -> assertThat(b).isEqualTo(expectedIterator.next()));
    assertThat(expectedIterator.hasNext()).isFalse();
  }

  private interface TypeB {}

  private static class HasBoth extends TypeA implements TypeB {}

  @GwtIncompatible // Iterables.filter(Iterable, Class)
  public void testFilterByType_iterator() throws Exception {
    HasBoth hasBoth = new HasBoth();
    Iterable<TypeA> alist = Lists.newArrayList(new TypeA(), new TypeA(), hasBoth, new TypeA());
    Iterable<TypeB> blist = filter(alist, TypeB.class);