return new TypeToken<Map<K, V>>() {}.where(new TypeParameter<K>() {}, keyType)
        .where(new TypeParameter<V>() {}, valueType);
  }

  private static <T> TypeToken<T[]> arrayOf(Class<T> componentType) {
    return new TypeToken<T[]>() {}.where(new TypeParameter<T>() {}, componentType);
  }

  public <T> void testNulls() {