/**
   * 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()}.
   */

   * until a nonzero result is found; imposes "dictionary order." If the end of one iterable is
   * reached, but not the other, the shorter iterable is considered to be less than the longer one.
   * For example, a lexicographical natural ordering over integers considers {@code [] < [1] < [1,
   * 1] < [1, 2] < [2]}.
   *

  @CheckForNull
  public abstract C next(C value);

  /**
   * Returns the unique greatest value of type {@code C} that is less than {@code value}, or {@code
   * null} if none exists. Inverse operation to {@link #next}.
   *
   * @param value any value of type {@code C}
   * @return the greatest value less than {@code value}, or {@code null} if {@code value} is {@code
   *     minValue()}
   */
  @CheckForNull

    return CollectCollectors.toImmutableSortedMap(
        comparator, keyFunction, valueFunction, mergeFunction);
  }

  /*
   * TODO(kevinb): Confirm that ImmutableSortedMap is faster to construct and
   * uses less memory than TreeMap; then say so in the class Javadoc.
   */
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =

    }

    @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;

   * @param size the size of that array, list or string
   * @return the value of {@code index}
   * @throws IndexOutOfBoundsException if {@code index} is negative or is not less than {@code size}
   * @throws IllegalArgumentException if {@code size} is negative
   */
  @CanIgnoreReturnValue
  public static int checkElementIndex(int index, int size) {

@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) {

    return CollectCollectors.toImmutableSortedMap(
        comparator, keyFunction, valueFunction, mergeFunction);
  }

  /*
   * TODO(kevinb): Confirm that ImmutableSortedMap is faster to construct and
   * uses less memory than TreeMap; then say so in the class Javadoc.
   */
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =