/**
   * 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
  public abstract C previous(C value);

  /**

    Double.NEGATIVE_INFINITY,
    -Double.MAX_VALUE,
    (double) Long.MIN_VALUE,
    (double) Integer.MIN_VALUE,
    -Math.PI,
    -1.0,
    -Double.MIN_VALUE,
    -0.0,
    +0.0,
    Double.MIN_VALUE,
    1.0,
    Math.PI,
    (double) Integer.MAX_VALUE,
    (double) Long.MAX_VALUE,
    Double.MAX_VALUE,
    Double.POSITIVE_INFINITY,
    Double.NaN,
    Float.MAX_VALUE,
  };

  }

  @Override
  public V get(Object key) {
    checkNotNull(key);
    Timestamped<V> value = cachingHashMap.get(key);

    if (value == null) {
      statsCounter.recordMisses(1);
      return null;
    } else if (!isExpired(value)) {
      statsCounter.recordHits(1);
      value.updateTimestamp();
      return value.getValue();
    } else {
      statsCounter.recordEviction();
      statsCounter.recordMisses(1);

    return generateListMultimap(key, value);
  }

  @Generates
  static <K, V> ImmutableMultimap<K, V> generateImmutableMultimap(K key, V value) {
    return ImmutableMultimap.of(key, value);
  }

  @Generates
  static <K, V> ListMultimap<K, V> generateListMultimap(@Nullable K key, @Nullable V value) {
    return generateArrayListMultimap(key, value);
  }

  @Generates

      return column;
    }

    @Override
    public V getValue() {
      return value;
    }

    void merge(V value, BinaryOperator<V> mergeFunction) {
      checkNotNull(value, "value");
      this.value = checkNotNull(mergeFunction.apply(this.value, value), "mergeFunction.apply");
    }
  }

  private static <R extends @Nullable Object, C extends @Nullable Object, V> void mergeTables(

  private Suppliers() {}

  /**
   * Returns a new supplier which is the composition of the provided function and supplier. In other
   * words, the new supplier's value will be computed by retrieving the value from {@code supplier},
   * and then applying {@code function} to that value. Note that the resulting supplier will not
   * call {@code supplier} or invoke {@code function} until it is called.
   */

      new float[] {
        LEAST,
        -Float.MAX_VALUE,
        -1f,
        -0f,
        0f,
        1f,
        Float.MAX_VALUE,
        GREATEST,
        Float.MIN_NORMAL,
        -Float.MIN_NORMAL,
        Float.MIN_VALUE,
        -Float.MIN_VALUE,
        Integer.MIN_VALUE,
        Integer.MAX_VALUE,
        Long.MIN_VALUE,
        Long.MAX_VALUE
      };

 * associated with a key and then add the key back to the multimap, that key will come last in the
 * key iteration order.
 *
 * <p>The multimap does not store duplicate key-value pairs. Adding a new key-value pair equal to an
 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *

public class TreeTraverserTest extends TestCase {
  private static class Node {
    final char value;

    Node(char value) {
      this.value = value;
    }
  }

  private static final class Tree extends Node {
    final List<Tree> children;

    public Tree(char value, Tree... children) {
      super(value);
      this.children = Arrays.asList(children);
    }
  }

public class MapMergeTester<K, V> extends AbstractMapTester<K, V> {
  @MapFeature.Require(SUPPORTS_PUT)
  public void testAbsent() {
    assertEquals(
        "Map.merge(absent, value, function) should return value",
        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(