assertFalse(
        from.getType() + " shouldn't be a subtype of " + to.getType(), from.isSubtypeOf(to));
  }

  private static void assertHasArrayInterfaces(TypeToken<?> arrayType) {
    assertEquals(arrayInterfaces(), ImmutableSet.copyOf(arrayType.getGenericInterfaces()));
  }

  private static ImmutableSet<TypeToken<?>> arrayInterfaces() {
    ImmutableSet.Builder<TypeToken<?>> builder = ImmutableSet.builder();