@Beta // TODO: b/288085449 - Remove.
  public static <T extends @Nullable Object> Collector<T, ?, List<T>> least(
      int k, Comparator<? super T> comparator) {
    checkNonnegative(k, "k");
    checkNotNull(comparator);
    return Collector.of(
        () -> TopKSelector.<T>least(k, comparator),
        TopKSelector::offer,
        TopKSelector::combine,
        TopKSelector::topK,

      currentWaiter.unpark();
    }
  }

  /**
   * Clears the {@link #listeners} list and prepends its contents to {@code onto}, least recently
   * added first.
   */
  @CheckForNull
  private Listener clearListeners(@CheckForNull Listener onto) {
    // We need to

   * collection. If the collection is an {@link EnumSet}, this method has the same behavior as
   * {@link EnumSet#complementOf}. Otherwise, the specified collection must contain at least one
   * element, in order to determine the element type. If the collection could be empty, use {@link
   * #complementOf(Collection, Class)} instead of this method.
   *

  }

  // Regular instance methods

  @Override
  public abstract int compare(@ParametricNullness T left, @ParametricNullness T right);

  /**
   * Returns the least of the specified values according to this ordering. If there are multiple
   * least values, the first of those is returned. The iterator will be left exhausted: its {@code
   * hasNext()} method will return {@code false}.
   *

 *
 * <p>This interface is now a legacy type. Use {@code java.util.function.Supplier} (or the
 * appropriate primitive specialization such as {@code IntSupplier}) instead whenever possible.
 * Otherwise, at least reduce <i>explicit</i> dependencies on this type by using lambda expressions
 * or method references instead of classes, leaving your code easier to migrate in the future.
 *

    /*
     * We'd normally use ServiceLoader here, but it hurts Android startup performance. To avoid
     * that, we hardcode the JDK Pattern compiler on Android (and, inadvertently, on App Engine and
     * in Guava, at least for now).
     */
    return new JdkPatternCompiler();
  }

  private static final class JdkPatternCompiler implements PatternCompiler {
    @Override
    public CommonPattern compile(String pattern) {

 * java.util.concurrent}, {@code java.util.regex}, {@code com.google.common.base}, {@code
 * com.google.common.collect} and {@code com.google.common.primitives}. In addition, if the type
 * exposes at least one public static final constant of the same type, one of the constants will be
 * used; or if the class exposes a public parameter-less constructor then it will be "new"d and
 * returned.
 *

 * java.util.concurrent}, {@code java.util.regex}, {@code com.google.common.base}, {@code
 * com.google.common.collect} and {@code com.google.common.primitives}. In addition, if the type
 * exposes at least one public static final constant of the same type, one of the constants will be
 * used; or if the class exposes a public parameter-less constructor then it will be "new"d and
 * returned.
 *

   * with linear probing in its implementation. The returned size is the smallest power of two that
   * can hold setSize elements with the desired load factor. Always returns at least setSize + 2.
   */
  @VisibleForTesting
  static int chooseTableSize(int setSize) {
    setSize = Math.max(setSize, 2);
    // Correct the size for open addressing to match desired load factor.

        contents = new ObjectCountLinkedHashMap<E>(contents);
        isLinkedHash = true;
        // to preserve insertion order through deletions, we have to switch to an actual linked
        // implementation at least for now, but this should be a super rare case
      } else if (buildInvoked) {
        contents = new ObjectCountHashMap<E>(contents);
        isLinkedHash = false;
      }
      buildInvoked = false;