boolean isEmpty() {
    // The casts are safe because of the has*Bound() checks.
    return (hasUpperBound() && tooLow(uncheckedCastNullableTToT(getUpperEndpoint())))
        || (hasLowerBound() && tooHigh(uncheckedCastNullableTToT(getLowerEndpoint())));
  }

  boolean tooLow(@ParametricNullness T t) {
    if (!hasLowerBound()) {
      return false;
    }
    // The cast is safe because of the hasLowerBound() check.

      keyList.count = 0;
      modCount++;
    } else {
      // requireNonNull is safe (under the conditions listed in the comment in the branch above).
      KeyList<K, V> keyList = requireNonNull(keyToKeyList.get(node.getKey()));
      keyList.count--;

      if (node.previousSibling == null) {
        // requireNonNull is safe because we checked that not *both* siblings were null.

   *
   */
  CacheStats stats();

  /**
   * Returns a view of the entries stored in this cache as a thread-safe map. Modifications made to
   * the map directly affect the cache.
   *
   * <p>Iterators from the returned map are at least <i>weakly consistent</i>: they are safe for
   * concurrent use, but if the cache is modified (including by eviction) after the iterator is

 * {@link #unmodifiableKeySet()}. By design, the cache is cleared when this structure is mutated. If
 * this structure is never mutated, it provides a thread-safe view of the backing map.
 *
 * <p>The {@link MapIteratorCache} assumes ownership of the backing map, and cannot guarantee
 * correctness in the face of external mutations to the backing map. As such, it is <b>strongly</b>

 * comparator is not consistent with {@code equals}.
 *
 * <p>The {@code standard} methods are not guaranteed to be thread-safe, even when all of the
 * methods that they depend on are thread-safe.
 *
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible

   *     wrap(Integer.class) == Integer.class
   *     wrap(String.class) == String.class
   * </pre>
   */
  public static <T> Class<T> wrap(Class<T> type) {
    checkNotNull(type);

    // cast is safe: long.class and Long.class are both of type Class<Long>
    @SuppressWarnings("unchecked")
    Class<T> wrapped = (Class<T>) PRIMITIVE_TO_WRAPPER_TYPE.get(type);
    return (wrapped == null) ? type : wrapped;
  }

   */
  @SuppressWarnings("unchecked") // Safe as long as the javadocs are followed
  static <K, V> ImmutableMapEntry<K, V>[] createEntryArray(int size) {
    return (ImmutableMapEntry<K, V>[]) new ImmutableMapEntry<?, ?>[size];
  }

  ImmutableMapEntry(K key, V value) {
    super(key, value);
    checkEntryNotNull(key, value);
  }

  // Redeclare methods to make them `final`, just to be extra-safe.

  @Override
  @ParametricNullness

 * invoke methods, they invoke methods on the {@code ForwardingBlockingDeque}.
 *
 * <p>The {@code standard} methods are not guaranteed to be thread-safe, even when all of the
 * methods that they depend on are thread-safe.
 *
 * @author Emily Soldal
 * @since 14.0
 * @deprecated This class has moved to {@code com.google.common.util.concurrent}. Please use {@link

      if (!columnIterator.hasNext()) {
        rowEntry = rowIterator.next();
        columnIterator = rowEntry.getValue().entrySet().iterator();
      }
      /*
       * requireNonNull is safe because:
       *
       * - columnIterator started off pointing to an empty iterator, so we must have entered the
       *   `if` body above at least once. Thus, if we got this far, that `if` body initialized

      switch (balanceFactor()) {
        case -2:
          // requireNonNull is safe because right must exist in order to get a negative factor.
          requireNonNull(right);
          if (right.balanceFactor() > 0) {
            right = right.rotateRight();
          }
          return rotateLeft();
        case 2:
          // requireNonNull is safe because left must exist in order to get a positive factor.