if (cal.hasClass('left')) {
                this.leftCalendar.month.subtract(1, 'month');
                if (this.linkedCalendars)
                    this.rightCalendar.month.subtract(1, 'month');
            } else {
                this.rightCalendar.month.subtract(1, 'month');
            }
            this.updateCalendars();
        },

        double z = a.getAndUpdate(value -> value + y);
        assertBitEquals(x, z);
        assertBitEquals(x + y, a.get());
      }
    }
  }

  /**
   * getAndUpdate with subtract stores subtraction of value from current, and returns previous value
   */
  public void testGetAndUpdateWithSubtract() {
    for (double x : VALUES) {
      for (double y : VALUES) {

      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();
    }

        } 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.
   *

    checkBigIntegerConversion(
        "::ffff:ffff:ffff:ffff", BigInteger.ONE.shiftLeft(64).subtract(BigInteger.ONE));
    checkBigIntegerConversion(
        "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff",
        BigInteger.ONE.shiftLeft(128).subtract(BigInteger.ONE));
  }

  public void testFromIpv4BigIntegerInputTooLarge() {
    IllegalArgumentException expected =
        assertThrows(

  }

  @AndroidIncompatible // slow
  public void testLessThanBranchFree() {
    for (long x : ALL_LONG_CANDIDATES) {
      for (long y : ALL_LONG_CANDIDATES) {
        BigInteger difference = BigInteger.valueOf(x).subtract(BigInteger.valueOf(y));
        if (fitsInLong(difference)) {
          int expected = (x < y) ? 1 : 0;
          int actual = LongMath.lessThanBranchFree(x, y);
          assertEquals(expected, actual);
        }

      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);
      }
    }
  }

	for left > 0 {
		// Read expected hash...
		h.Reset()
		n, err := io.ReadFull(r, hashBuf)
		if err != nil {
			// Read's failed for object with right size, file is corrupt.
			return err
		}
		// Subtract hash length..
		left -= int64(n)
		if left < shardSize {
			shardSize = left
		}

		read, err := io.CopyBuffer(h, io.LimitReader(r, shardSize), *bufp)
		if err != nil {

  }

  @AndroidIncompatible // slow
  public void testCheckedSubtract() {
    for (int a : ALL_INTEGER_CANDIDATES) {
      for (int b : ALL_INTEGER_CANDIDATES) {
        BigInteger expectedResult = valueOf(a).subtract(valueOf(b));
        boolean expectedSuccess = fitsInInt(expectedResult);
        try {
          assertEquals(a - b, IntMath.checkedSubtract(a, b));
          assertTrue(expectedSuccess);

    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.
   */