@GwtIncompatible // SerializableTester
  public void testKeySetIsSerializable_jdkBackedImmutableMap() {
    class NonSerializableClass {}

    Entry<String, NonSerializableClass>[] entries =
        arrayOf(ImmutableMap.entryOf("one", new NonSerializableClass()));

    ImmutableMap<String, NonSerializableClass> map =
        JdkBackedImmutableMap.create(1, entries, /* throwIfDuplicateKeys= */ true);

    // Type inference is doomed here: int.class is the same as Integer.class, so this is comparing
    // TypeToken<int[]> and TypeToken<Integer[]>.
    assertEquals(new TypeToken<int[]>() {}, arrayOf(int.class));
    assertEquals(int[].class, arrayOf(int.class).getRawType());
  }

  @SuppressWarnings("unused") // used by reflection
  private static class Holder<T> {
    List<T>[] matrix;

    void setList(List<T> list) {}

    // Type inference is doomed here: int.class is the same as Integer.class, so this is comparing
    // TypeToken<int[]> and TypeToken<Integer[]>.
    assertEquals(new TypeToken<int[]>() {}, arrayOf(int.class));
    assertEquals(int[].class, arrayOf(int.class).getRawType());
  }

  @SuppressWarnings("unused") // used by reflection
  private static class Holder<T> {
    List<T>[] matrix;

    void setList(List<T> list) {}