assertEquals(c.getKey(), navigableMap.lastKey());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testHeadMapExclusive() {
    assertFalse(navigableMap.headMap(a.getKey()).containsKey(a.getKey()));
  }

  @CollectionSize.Require(absent = ZERO)
  public void testTailMapInclusive() {
    assertTrue(navigableMap.tailMap(a.getKey()).containsKey(a.getKey()));
  }

  public void testHeadMap() {

    assertTrue(
        "add(somePresent) should return true", getSet().addAll(MinimalCollection.of(e3(), e0())));
    expectAdded(e3());
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_withDuplicates() {
    MinimalCollection<E> elementsToAdd = MinimalCollection.of(e3(), e4(), e3(), e4());
    assertTrue("add(hasDuplicates) should return true", getSet().addAll(elementsToAdd));
    expectAdded(e3(), e4());
  }

    RangeMapEntry(Range<K> range, V value) {
      super(range, value);
    }

    boolean contains(K value) {
      return getKey().contains(value);
    }

    Cut<K> getLowerBound() {
      return getKey().lowerBound;
    }

    Cut<K> getUpperBound() {
      return getKey().upperBound;
    }
  }

  @Override
  public @Nullable V get(K key) {
    Entry<Range<K>, V> entry = getEntry(key);

      entryArray[i] = e;
      V oldValue = forwardDelegate.putIfAbsent(e.getKey(), e.getValue());
      if (oldValue != null) {
        throw conflictException("key", e.getKey() + "=" + oldValue, entryArray[i]);
      }
      K oldKey = backwardDelegate.putIfAbsent(e.getValue(), e.getKey());
      if (oldKey != null) {
        throw conflictException("value", oldKey + "=" + e.getValue(), entryArray[i]);

                    BiMap<String, String> bimap = HashBiMap.create(entries.length);
                    for (Entry<String, String> entry : entries) {
                      checkArgument(!bimap.containsKey(entry.getKey()));
                      bimap.put(entry.getKey(), entry.getValue());
                    }
                    return Maps.unmodifiableBiMap(bimap);
                  }
                })
            .named("unmodifiableBiMap[HashBiMap]")

      assertFalse(
          "Inverse should not contain entry " + reversed, inv.entrySet().contains(reversed));
      assertFalse(
          "Inverse should not contain key " + reversed.getKey(),
          inv.containsKey(reversed.getKey()));
      assertFalse(
          "Inverse should not contain value " + reversed.getValue(),
          inv.containsValue(reversed.getValue()));
      /*

        Entry<Object, Object> entry = warmed.get(i - WARMUP_MIN);
        assertThat(cache.asMap().containsKey(entry.getKey())).isTrue();
        assertThat(cache.asMap().containsValue(entry.getValue())).isTrue();
        // this getUnchecked() call shouldn't be a cache miss; verified below
        assertThat(cache.getUnchecked(entry.getKey())).isEqualTo(entry.getValue());
      }
      assertThat(cache.stats().missCount()).isEqualTo(WARMUP_SIZE);

    for (ListIterator<Entry<K, V>> i = expected.listIterator(); i.hasNext(); ) {
      if (Helpers.equal(i.next().getKey(), newEntry.getKey())) {
        i.set(newEntry);
        return;
      }
    }

    throw new IllegalArgumentException(
        Platform.format("key %s not found in entries %s", newEntry.getKey(), expected));
  }

  /**

    private static <T> Map<AccessorKey, T> diff(Map<AccessorKey, T> first, Map<AccessorKey, T> second) {
        return first.entrySet().stream()
            .filter(e -> !second.containsKey(e.getKey()))
            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
    }

        public int compare(Entry<AnEnum, String> left, Entry<AnEnum, String> right) {
          return left.getKey().compareTo(right.getKey());
        }
      }.sortedCopy(insertionOrder);
    }
  }

  public static class ImmutableMapValuesAsSingletonSetGenerator
      implements TestMapGenerator<String, Collection<Integer>> {

    @Override
    public SampleElements<Entry<String, Collection<Integer>>> samples() {