* amortized since some operations can trigger a hash table resize.
 *
 * <p>This implementation consumes significantly less memory than {@code java.util.LinkedHashSet} or
 * even {@code java.util.HashSet}, and places considerably less load on the garbage collector. Like
 * {@code java.util.LinkedHashSet}, it offers insertion-order iteration, with identical behavior.
 *

    }

    @Override
    public Map<String, Collection<Integer>> create(Object... elements) {
      ImmutableMap.Builder<String, Integer> builder = ImmutableMap.builder();
      // assumes that each set is a singleton or less (as is done for the samples)
      for (Object elem : elements) {
        @SuppressWarnings("unchecked") // safe by generator contract
        Entry<String, Collection<Integer>> entry = (Entry<String, Collection<Integer>>) elem;

@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class TreeMultimapExplicitTest extends TestCase {

  /**
   * Compare strings lengths, and if the lengths are equal compare the strings. A {@code null} is
   * less than any non-null value.
   */
  private enum StringLength implements Comparator<@Nullable String> {
    COMPARATOR;

    @Override
    public int compare(@Nullable String first, @Nullable String second) {

  /**
   * Returns an element less than the {@link #samples()} and less than {@link
   * #belowSamplesGreater()}.
   */
  E belowSamplesLesser();

  /**
   * Returns an element less than the {@link #samples()} but greater than {@link
   * #belowSamplesLesser()}.
   */
  E belowSamplesGreater();

  /**
   * Returns an element greater than the {@link #samples()} but less than {@link
   * #aboveSamplesGreater()}.

  /**
   * Returns an element less than the {@link #samples()} and less than {@link
   * #belowSamplesGreater()}.
   */
  E belowSamplesLesser();

  /**
   * Returns an element less than the {@link #samples()} but greater than {@link
   * #belowSamplesLesser()}.
   */
  E belowSamplesGreater();

  /**
   * Returns an element greater than the {@link #samples()} but less than {@link
   * #aboveSamplesGreater()}.

  @Override
  SortedMap<K, V> create(Object... elements);

  /**
   * Returns an entry with a key less than the keys of the {@link #samples()} and less than the key
   * of {@link #belowSamplesGreater()}.
   */
  Entry<K, V> belowSamplesLesser();

  /**
   * Returns an entry with a key less than the keys of the {@link #samples()} but greater than the
   * key of {@link #belowSamplesLesser()}.
   */

   * The new array contains nulls, even if the old array did not. If we wanted to be accurate, we
   * would declare a return type of `@Nullable T[]`. However, we've decided not to think too hard
   * about arrays for now, as they're a mess. (We previously discussed this in the review of
   * ObjectArrays, which is the main caller of this method.)
   */
  static <T extends @Nullable Object> T[] newArray(T[] reference, int length) {

 * amortized since some operations can trigger a hash table resize.
 *
 * <p>This implementation consumes significantly less memory than {@code java.util.LinkedHashSet} or
 * even {@code java.util.HashSet}, and places considerably less load on the garbage collector. Like
 * {@code java.util.LinkedHashSet}, it offers insertion-order iteration, with identical behavior.
 *

    return (Ordering<@Nullable S>) result;
  }

  @Override
  public <S extends Comparable<?>> Ordering<S> reverse() {
    return (Ordering<S>) ReverseNaturalOrdering.INSTANCE;
  }

  // preserving singleton-ness gives equals()/hashCode() for free
  private Object readResolve() {
    return INSTANCE;
  }

  @Override
  public String toString() {
    return "Ordering.natural()";
  }

  private NaturalOrdering() {}

 * a {@link RoundingMode}.
 */
@GwtIncompatible
@ElementTypesAreNonnullByDefault
abstract class ToDoubleRounder<X extends Number & Comparable<X>> {
  /**
   * Returns x rounded to either the greatest double less than or equal to the precise value of x,
   * or the least double greater than or equal to the precise value of x.
   */
  abstract double roundToDoubleArbitrarily(X x);

  /** Returns the sign of x: either -1, 0, or 1. */