*   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>to be replaced with the more compact
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   checkArgument(value >= 0, "input is negative: %s", value);
 *   // calculate square root
 * }
 * }</pre>
 *

 *   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>to be replaced with the more compact
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   checkArgument(value >= 0, "input is negative: %s", value);
 *   // calculate square root
 * }
 * }</pre>
 *

    WEAK {
      @Override
      Equivalence<Object> defaultEquivalence() {
        return Equivalence.identity();
      }
    };

    /**
     * Returns the default equivalence strategy used to compare and hash keys or values referenced
     * at this strength. This strategy will be used unless the user explicitly specifies an
     * alternate strategy.
     */
    abstract Equivalence<Object> defaultEquivalence();
  }

    if (set.comparator() != null
        && set.comparator() != Ordering.natural()
        && range.hasLowerBound()
        && range.hasUpperBound()) {
      checkArgument(
          set.comparator().compare(range.lowerEndpoint(), range.upperEndpoint()) <= 0,
          "set is using a custom comparator which is inconsistent with the natural ordering.");
    }
    if (range.hasLowerBound() && range.hasUpperBound()) {

 * Comparator} or {@link Comparable} type whose comparison behavior is <i>inconsistent with
 * equals</i>. That is, {@code a.compareTo(b)} or {@code comparator.compare(a, b)} should equal zero
 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting map will
 * not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=

 * Comparator} or {@link Comparable} type whose comparison behavior is <i>inconsistent with
 * equals</i>. That is, {@code a.compareTo(b)} or {@code comparator.compare(a, b)} should equal zero
 * <i>if and only if</i> {@code a.equals(b)}. If this advice is not followed, the resulting map will
 * not correctly obey its specification.
 *
 * <p>See the Guava User Guide article on <a href=

      // to be sorted based on the top of each iterator.
      Comparator<PeekingIterator<T>> heapComparator =
          (PeekingIterator<T> o1, PeekingIterator<T> o2) ->
              itemComparator.compare(o1.peek(), o2.peek());

      queue = new PriorityQueue<>(2, heapComparator);

      for (Iterator<? extends T> iterator : iterators) {
        if (iterator.hasNext()) {

      // to be sorted based on the top of each iterator.
      Comparator<PeekingIterator<T>> heapComparator =
          (PeekingIterator<T> o1, PeekingIterator<T> o2) ->
              itemComparator.compare(o1.peek(), o2.peek());

      queue = new PriorityQueue<>(2, heapComparator);

      for (Iterator<? extends T> iterator : iterators) {
        if (iterator.hasNext()) {

                    /*
                     * TODO Extensions like Flex Mojos use custom scopes like "merged", "internal", "external", etc. In
                     * order to don't break backward-compat with those, only warn but don't error out.
                     */
                    validateEnum(
                            prefix,
                            "scope",
                            problems,

   * higher value than you need can waste space and time, and a significantly lower value can lead
   * to thread contention. But overestimates and underestimates within an order of magnitude do not
   * usually have much noticeable impact. A value of one permits only one thread to modify the cache
   * at a time, but since read operations and cache loading computations can proceed concurrently,
   * this still yields higher concurrency than full synchronization.