public void testIn_serialization() {
    checkSerialization(Predicates.in(Arrays.asList(1, 2, 3, null)));
  }

  public void testIn_handlesNullPointerException() {
    class CollectionThatThrowsNullPointerException<T> extends ArrayList<T> {
      @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 1L;

      @Override
      public boolean contains(@Nullable Object element) {