}

  public void testIsPowerOfTwo() {
    for (BigInteger x : ALL_BIGINTEGER_CANDIDATES) {
      // Checks for a single bit set.
      boolean expected = x.signum() > 0 & x.and(x.subtract(ONE)).equals(ZERO);
      assertEquals(expected, BigIntegerMath.isPowerOfTwo(x));
    }
  }

  public void testLog2ZeroAlwaysThrows() {
    for (RoundingMode mode : ALL_ROUNDING_MODES) {

    }

    @Override
    BigDecimal toX(double d, RoundingMode mode) {
      return new BigDecimal(d);
    }

    @Override
    BigDecimal minus(BigDecimal a, BigDecimal b) {
      return a.subtract(b);
    }
  }

    key: KClass<T>,
    value: T?,
  ): Tags {
    // Create a copy of this `LinkedTags` that doesn't have a mapping for `key`.
    val thisMinusKey =
      when {
        key == this.key -> next // Subtract this!

        else -> {
          val nextMinusKey = next.plus(key, null)
          when {
            nextMinusKey === next -> this // Same as the following line, but with fewer allocations.

        } else if (nanos <= 0) {
          return false;
        } else {
          long now = System.nanoTime();
          NANOSECONDS.timedWait(lock, nanos);
          nanos -= System.nanoTime() - now; // subtract the actual time we waited
        }
      }
    }
  }

  /**
   * Checks if the executor has been shut down and increments the running task count.
   *

    }

    @Override
    BigDecimal toX(double d, RoundingMode mode) {
      return new BigDecimal(d);
    }

    @Override
    BigDecimal minus(BigDecimal a, BigDecimal b) {
      return a.subtract(b);
    }
  }

      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) {
      return end.subtract(start).max(MIN_LONG).min(MAX_LONG).longValue();
    }

    requireLinks()[i] = value;
  }

  /*
   * We don't define getPredecessor+getSuccessor and setPredecessor+setSuccessor here because
   * they're defined above -- including logic to add and subtract 1 to map between the values stored
   * in the predecessor/successor arrays and the indexes in the elements array that they identify.
   */

            513,
            Double.MAX_EXPONENT - 1,
            Double.MAX_EXPONENT,
            Double.MAX_EXPONENT + 1)) {
      BigInteger x = ONE.shiftLeft(exponent);
      bigValues.add(x, x.add(ONE), x.subtract(ONE));
    }
    bigValues.add(new BigInteger("218838949120258359057546633")); // sqrt(2^175) rounded up and
    // down
    bigValues.add(new BigInteger("218838949120258359057546634"));

      for (long b : TEST_LONGS) {
        UnsignedLong aUnsigned = UnsignedLong.fromLongBits(a);
        UnsignedLong bUnsigned = UnsignedLong.fromLongBits(b);
        long expected =
            aUnsigned.bigIntegerValue().subtract(bUnsigned.bigIntegerValue()).longValue();
        UnsignedLong unsignedSub = aUnsigned.minus(bUnsigned);
        assertThat(unsignedSub.longValue()).isEqualTo(expected);
      }
    }
  }

        .setExpectation(-Double.MAX_VALUE, RoundingMode.values())
        .test();
  }

  public void testRoundToDouble_minDoubleMinusOne() {
    BigDecimal minDoubleAsBigDecimal = new BigDecimal(-Double.MAX_VALUE).subtract(BigDecimal.ONE);
    new RoundToDoubleTester(minDoubleAsBigDecimal)
        .setExpectation(-Double.MAX_VALUE, DOWN, CEILING, HALF_EVEN, HALF_UP, HALF_DOWN)
        .setExpectation(Double.NEGATIVE_INFINITY, UP, FLOOR)