return RANDOM_SOURCE.nextBoolean() ? result : result.negate();
  }

  /**
   * Chooses a number in (-2^numBits, 2^numBits) at random, with density concentrated in numbers of
   * lower magnitude.
   */
  static BigInteger randomBigInteger(int numBits) {
    while (true) {
      if (RANDOM_SOURCE.nextBoolean()) {
        return randomNonNegativeBigInteger(numBits);
      }

    return RANDOM_SOURCE.nextBoolean() ? result : result.negate();
  }

  /**
   * Chooses a number in (-2^numBits, 2^numBits) at random, with density concentrated in numbers of
   * lower magnitude.
   */
  static BigInteger randomBigInteger(int numBits) {
    while (true) {
      if (RANDOM_SOURCE.nextBoolean()) {
        return randomNonNegativeBigInteger(numBits);
      }

  protected MonitorTestCase(boolean interruptible) {
    this.interruptible = interruptible;
  }

  @Override
  protected final void setUp() throws Exception {
    boolean fair = new Random().nextBoolean();
    monitor = new Monitor(fair);
    tearDownStack.addTearDown(thread1 = new TestThread<>(monitor, "TestThread #1"));
    tearDownStack.addTearDown(thread2 = new TestThread<>(monitor, "TestThread #2"));
  }