if (comparator != null) { // can't use ? : because of javac bug 5080917
      return comparator;
    }
    return (Comparator<E>) Ordering.natural();
  }

  /**
   * Returns a live {@link Map} view whose keys are the contents of {@code set} and whose values are
   * computed on demand using {@code function}. To get an immutable <i>copy</i> instead, use {@link
   * #toMap(Iterable, Function)}.
   *

    map.put(four, five);
    i = map.keySet().iterator();
    i.next();
    i.remove();
    assertNotified(listener, four, five, RemovalCause.EXPLICIT);

    map.put(five, six);
    i = map.values().iterator();
    i.next();
    i.remove();
    assertNotified(listener, five, six, RemovalCause.EXPLICIT);

    assertTrue(listener.isEmpty());
  }

    assertNotified(listener, three, four, RemovalCause.EXPLICIT);

    map.put(four, five);
    i = map.keySet().iterator();
    i.next();
    i.remove();
    assertNotified(listener, four, five, RemovalCause.EXPLICIT);

    map.put(five, six);
    i = map.values().iterator();
    i.next();
    i.remove();
    assertNotified(listener, five, six, RemovalCause.EXPLICIT);

    assertTrue(listener.isEmpty());
  }

     * comments.
     */

    @Weak final LocalCache<K, V> map;

    /** The number of live elements in this segment's region. */
    volatile int count;

    /** The weight of the live elements in this segment's region. */
    @GuardedBy("this")
    long totalWeight;

    /**

     * comments.
     */

    @Weak final LocalCache<K, V> map;

    /** The number of live elements in this segment's region. */
    volatile int count;

    /** The weight of the live elements in this segment's region. */
    @GuardedBy("this")
    long totalWeight;

    /**

     * <pre>
     * message: Login failed.
     * comment:
     * /- - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     * five framework-embedded messages (don't change key names)
     * - - - - - - - - - -/
     * </pre>
     * @param property The property name for the message. (NotNull)
     * @return this. (NotNull)
     */

          ClosingFuture<V3> future3,
          ClosingFuture<V4> future4) {
    return new Combiner4<>(future1, future2, future3, future4);
  }

  /**
   * Starts specifying how to combine five {@link ClosingFuture}s into a single pipeline, assuming
   * they all succeed. If any fail, the resulting pipeline will fail.
   *
   * <p>Calling this method allows you to use lambdas or method references typed with the types of