}

    @Override
    public BigInteger previous(BigInteger value) {
      return value.subtract(BigInteger.ONE);
    }

    @Override
    BigInteger offset(BigInteger origin, long distance) {
      checkNonnegative(distance, "distance");
      return origin.add(BigInteger.valueOf(distance));
    }

    @Override
    public long distance(BigInteger start, BigInteger end) {

    }

    @Override
    public BigInteger previous(BigInteger value) {
      return value.subtract(BigInteger.ONE);
    }

    @Override
    BigInteger offset(BigInteger origin, long distance) {
      checkNonnegative(distance, "distance");
      return origin.add(BigInteger.valueOf(distance));
    }

    @Override
    public long distance(BigInteger start, BigInteger end) {

      implements TestSetGenerator<BigInteger> {
    @Override
    public SampleElements<BigInteger> samples() {
      return new SampleElements<>(
          BigInteger.valueOf(1),
          BigInteger.valueOf(4),
          BigInteger.valueOf(3),
          BigInteger.valueOf(2),
          BigInteger.valueOf(5));
    }

    @Override
    public BigInteger[] createArray(int length) {

    double roundToDoubleArbitrarily(BigInteger bigInteger) {
      return DoubleUtils.bigToDouble(bigInteger);
    }

    @Override
    int sign(BigInteger bigInteger) {
      return bigInteger.signum();
    }

    @Override
    BigInteger toX(double d, RoundingMode mode) {
      return DoubleMath.roundToBigInteger(d, mode);
    }

    @Override
    BigInteger minus(BigInteger a, BigInteger b) {

    }
  }

  /** Previous version of BigIntegerMath.factorial, kept for timing purposes. */
  private static BigInteger oldSlowFactorial(int n) {
    if (n <= 20) {
      return BigInteger.valueOf(LongMath.factorial(n));
    } else {
      int k = 20;
      return BigInteger.valueOf(LongMath.factorial(k)).multiply(oldSlowFactorial(k, n));
    }
  }

    return bigMean.longValueExact();
  }

  private static boolean fitsInLong(BigInteger big) {
    return big.bitLength() <= 63;
  }

  private static final BigInteger MAX_LONG = BigInteger.valueOf(Long.MAX_VALUE);
  private static final BigInteger MIN_LONG = BigInteger.valueOf(Long.MIN_VALUE);

  private static long saturatedCast(BigInteger big) {
    if (big.compareTo(MAX_LONG) > 0) {
      return Long.MAX_VALUE;
    }

     */
    public static BigInteger toBigInteger(final Object o) {
        return toBigInteger(o, null);
    }

    /**
     * Converts to {@link BigInteger}.
     *
     * @param o
     *            The object to convert
     * @param pattern
     *            The pattern string
     * @return The converted {@link BigInteger}
     */

      }
    }
  }

  @GwtIncompatible // TODO
  public void testSqrtHalfUp() {
    for (BigInteger x : POSITIVE_BIGINTEGER_CANDIDATES) {
      BigInteger result = BigIntegerMath.sqrt(x, HALF_UP);
      BigInteger plusHalfSquared = result.pow(2).add(result).shiftLeft(2).add(ONE);
      BigInteger x4 = x.shiftLeft(2);
      // sqrt(x) < result + 0.5, so 4 * x < (result + 0.5)^2 * 4

        @Override
        public Long apply(Long x) {
          return -x;
        }
      };

  private static final Function<BigInteger, BigInteger> NEGATE_BIGINT =
      new Function<BigInteger, BigInteger>() {
        @Override
        public BigInteger apply(BigInteger x) {
          return x.negate();
        }
      };

  /*

      }
    }
  }

  private static final BigInteger MAX_INT = BigInteger.valueOf(Integer.MAX_VALUE);
  private static final BigInteger MIN_INT = BigInteger.valueOf(Integer.MIN_VALUE);

  private static int saturatedCast(BigInteger big) {
    if (big.compareTo(MAX_INT) > 0) {
      return Integer.MAX_VALUE;
    }
    if (big.compareTo(MIN_INT) < 0) {