}

    @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();
    }

        when:
        FileCollection sum = collection1 + collection2

        then:
        sum instanceof UnionFileCollection
        sum.getFiles() == toLinkedSet(file1, file2, file3)
    }

    def "can subtract a collection"() {
        File file1 = new File("f1")
        File file2 = new File("f2")
        File file3 = new File("f3")
        TestFileCollection collection1 = new TestFileCollection(file1, file2)

        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) {

    }

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

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

        BigDecimal averageValue = average.toUnits(baseUnits).getValue();
        for (Amount<Q> amount : this) {
            BigDecimal diff = amount.toUnits(baseUnits).getValue();
            diff = diff.subtract(averageValue);
            diff = diff.multiply(diff);
            sumSquares = sumSquares.add(diff);
        }
        // This isn't quite right, as we may lose precision when converting to a double

  if is_leader; then
    ensure_addons
    reconcile_addons
  else
    log INFO "Not elected leader, going back to sleep."
  fi
  end_sec=$(date +"%s")
  len_sec=$((end_sec-start_sec))
  # subtract the time passed from the sleep time
  if [[ ${len_sec} -lt ${ADDON_CHECK_INTERVAL_SEC} ]]; then
    sleep_time=$((ADDON_CHECK_INTERVAL_SEC-len_sec))
    sleep ${sleep_time}
  fi

        clickNext: function(e)...

      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();
    }

}

// subtract takes the addrRange toPrune and cuts out any overlap with
// from, then returns the new range. subtract assumes that a and b
// either don't overlap at all, only overlap on one side, or are equal.
// If b is strictly contained in a, thus forcing a split, it will throw.
func (a addrRange) subtract(b addrRange) addrRange {