return Class.forName("sun.misc.FpUtils").getMethod("nextDown", double.class);
    }
  }

  @AndroidIncompatible // TODO(cpovirk): File bug for BigDecimal.doubleValue().
  public void testBigToDouble() {
    for (BigInteger b : ALL_BIGINTEGER_CANDIDATES) {
      if (b.doubleValue() != DoubleUtils.bigToDouble(b)) {
        failFormat(
            "Converting %s to double: expected doubleValue %s but got bigToDouble %s",