* of signaling the next waiter.
   *
   * Unlike the underlying Condition, if we are not careful, an interrupt *can* cause a signal to be
   * lost, because the signal may be sent to a condition whose sole waiter has just been
   * interrupted.
   *
   * Imagine a monitor with multiple guards. A thread enters the monitor, satisfies all the guards,

   * a "hole" in it so that set tests of {@code ContiguousSet} can suppress them with {@code
   * FeatureSpecificTestSuiteBuilder.suppressing()}.
   */
  /*
   * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
   * implementations are permitted to throw IAE if a hole is requested, and we could update

        return minChildIndex;
      }
      return crossOverUp(index, x);
    }

    /**
     * Fills the hole at {@code index} by moving in the least of its grandchildren to this position,
     * then recursively filling the new hole created.
     *
     * @return the position of the new hole (where the lowest grandchild moved from, that had no
     *     grandchild to replace it)
     */
    int fillHoleAt(int index) {

    protected final ContiguousSet<Integer> checkedCreate(SortedSet<Integer> elementsSet) {
      List<Integer> elements = newArrayList(elementsSet);
      /*
       * A ContiguousSet can't have holes. If a test demands a hole, it should be changed so that it
       * doesn't need one, or it should be suppressed for ContiguousSet.
       */
      for (int i = 0; i < elements.size() - 1; i++) {

   * deal with overflow, then stored permits could be given out /slower/ than fresh ones. Thus, we
   * require a (different in each case) function that translates storedPermits to throttling time.
   *
   * This role is played by storedPermitsToWaitTime(double storedPermits, double permitsToTake). The
   * underlying model is a continuous function mapping storedPermits (from 0.0 to maxStoredPermits)

final class MathPreconditions {
  @CanIgnoreReturnValue
  static int checkPositive(String role, int x) {
    if (x <= 0) {
      throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
    }
    return x;
  }

  @CanIgnoreReturnValue
  static long checkPositive(String role, long x) {
    if (x <= 0) {
      throw new IllegalArgumentException(role + " (" + x + ") must be > 0");
    }
    return x;
  }

   * a "hole" in it so that set tests of {@code ContiguousSet} can suppress them with {@code
   * FeatureSpecificTestSuiteBuilder.suppressing()}.
   */
  /*
   * TODO(cpovirk): or we could make HOLES_FORBIDDEN a feature. Or we could declare that
   * implementations are permitted to throw IAE if a hole is requested, and we could update

    protected final ContiguousSet<Integer> checkedCreate(SortedSet<Integer> elementsSet) {
      List<Integer> elements = newArrayList(elementsSet);
      /*
       * A ContiguousSet can't have holes. If a test demands a hole, it should be changed so that it
       * doesn't need one, or it should be suppressed for ContiguousSet.
       */
      for (int i = 0; i < elements.size() - 1; i++) {