int delta = a - b; // can't overflow, since a and b are nonnegative

      int minDeltaOrZero = delta & (delta >> (Integer.SIZE - 1));
      // equivalent to Math.min(delta, 0)

      a = delta - minDeltaOrZero - minDeltaOrZero; // sets a to Math.abs(a - b)
      // a is now nonnegative and even

      b += minDeltaOrZero; // sets b to min(old a, b)

  abstract int sign(X x);

  /** Returns d's value as an X, rounded with the specified mode. */
  abstract X toX(double d, RoundingMode mode);

  /** Returns a - b, guaranteed that both arguments are nonnegative. */
  abstract X minus(X a, X b);

  /** Rounds {@code x} to a {@code double}. */
  final double roundToDouble(X x, RoundingMode mode) {
    checkNotNull(x, "x");
    checkNotNull(mode, "mode");

      long delta = a - b; // can't overflow, since a and b are nonnegative

      long minDeltaOrZero = delta & (delta >> (Long.SIZE - 1));
      // equivalent to Math.min(delta, 0)

      a = delta - minDeltaOrZero - minDeltaOrZero; // sets a to Math.abs(a - b)
      // a is now nonnegative and even

      b += minDeltaOrZero; // sets b to min(old a, b)

   *
   * <p><b>Java 11+ users:</b> use {@code string.repeat(count)} instead.
   *
   * @param string any non-null string
   * @param count the number of times to repeat it; a nonnegative integer
   * @return a string containing {@code string} repeated {@code count} times (the empty string if
   *     {@code count} is zero)
   * @throws IllegalArgumentException if {@code count} is negative
   */

          x >>>= shift;
        } while (x != 0);
      } else {
        // Separate off the last digit using unsigned division. That will leave
        // a number that is nonnegative as a signed integer.
        long quotient;
        if ((radix & 1) == 0) {
          // Fast path for the usual case where the radix is even.
          quotient = (x >>> 1) / (radix >>> 1);
        } else {

   * example, {@code repeat("hey", 3)} returns the string {@code "heyheyhey"}.
   *
   * @param string any non-null string
   * @param count the number of times to repeat it; a nonnegative integer
   * @return a string containing {@code string} repeated {@code count} times (the empty string if
   *     {@code count} is zero)
   * @throws IllegalArgumentException if {@code count} is negative
   */

  }

  // Query Operations

  /**
   * Returns the number of occurrences of {@code element} in this multiset.
   *
   * @param element the element to look for
   * @return the nonnegative number of occurrences of the element
   */
  @Override
  public int count(@Nullable Object element) {
    AtomicInteger existingCounter = safeGet(countMap, element);

  }

  // Query Operations

  /**
   * Returns the number of occurrences of {@code element} in this multiset.
   *
   * @param element the element to look for
   * @return the nonnegative number of occurrences of the element
   */
  @Override
  public int count(@Nullable Object element) {
    AtomicInteger existingCounter = safeGet(countMap, element);

   * start}, calling {@link #matches} for each character.
   *
   * @param sequence the character sequence to examine
   * @param start the first index to examine; must be nonnegative and no greater than {@code
   *     sequence.length()}
   * @return the index of the first matching character, guaranteed to be no less than {@code start},
   *     or {@code -1} if no character matches

   * start}, calling {@link #matches} for each character.
   *
   * @param sequence the character sequence to examine
   * @param start the first index to examine; must be nonnegative and no greater than {@code
   *     sequence.length()}
   * @return the index of the first matching character, guaranteed to be no less than {@code start},
   *     or {@code -1} if no character matches