}

  static class SerializableCountingSupplier extends CountingSupplier implements Serializable {
    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0L;
  }

  static class SerializableThrowingSupplier extends ThrowingSupplier implements Serializable {
    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0L;
  }