FALSE,
    MAYBE,
    TRUE,
  }

  static class Foo {
    private final String aString;
    private final int anInt;
    private final @Nullable TriState anEnum;

    Foo(String aString, int anInt, @Nullable TriState anEnum) {
      this.aString = aString;
      this.anInt = anInt;
      this.anEnum = anEnum;
    }

    @Override
    public String toString() {
      return toStringHelper(this)