SortedMap<String, Integer> subMap = map.subMap("a", "b");
    assertTrue(subMap instanceof SynchronizedSortedMap);
    assertSame(mutex, ((SynchronizedSortedMap<String, Integer>) subMap).mutex);
  }

  public void testSubMap_k_b_k_b() {
    NavigableMap<String, Integer> map = create();
    NavigableMap<String, Integer> subMap = map.subMap("a", true, "b", false);
    assertTrue(subMap instanceof SynchronizedNavigableMap);

    }

    @Override
    public Entry<K, V>[] createArray(int length) {
      return delegate.createArray(length);
    }
  }

  /** Two bounds (from and to) define how to build a subMap. */
  public enum Bound {
    INCLUSIVE,
    EXCLUSIVE,
    NO_BOUND;
  }

  public static class SortedSetSubsetTestSetGenerator<E extends @Nullable Object>
      implements TestSortedSetGenerator<E> {

    Set<Feature<?>> keySetFeatures = computeCommonDerivedCollectionFeatures(mapFeatures);

    // TODO(lowasser): make this trigger only if the map is a submap
    // currently, the KeySetGenerator won't work properly for a subset of a keyset of a submap
    keySetFeatures.add(CollectionFeature.SUBSET_VIEW);
    if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEYS)) {
      keySetFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);

    }
    return headMap(toKey);
  }

  public ImmutableSortedMap<K, V> subMap(K fromKey, K toKey) {
    checkNotNull(fromKey);
    checkNotNull(toKey);
    checkArgument(comparator.compare(fromKey, toKey) <= 0);
    return newView(sortedDelegate.subMap(fromKey, toKey));
  }

  ImmutableSortedMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
    checkNotNull(fromKey);

      return o != null
          && (lowerBound == null || compare(lowerBound, o) <= 0)
          && (upperBound == null || compare(upperBound, o) > 0);
    }

    @Override
    public SortedMap<C, V> subMap(C fromKey, C toKey) {
      checkArgument(rangeContains(checkNotNull(fromKey)) && rangeContains(checkNotNull(toKey)));
      return new TreeRow(rowKey, fromKey, toKey);
    }

    @Override

        putRangeMapEntry(
            rangeToRemove.upperBound,
            rangeMapEntry.getUpperBound(),
            mapEntryAboveToTruncate.getValue().getValue());
      }
    }
    entriesByLowerBound.subMap(rangeToRemove.lowerBound, rangeToRemove.upperBound).clear();
  }

  private void split(Cut<K> cut) {
    /*
     * The comments for this method will use | to indicate the cut point and ( ) to indicate the

                allEntries.addAll(normalValues);
                SortedMultiset<E> multiset =
                    (SortedMultiset<E>) delegate.create(allEntries.toArray());

                // call the smallest subMap overload that filters out the extreme
                // values
                if (from == Bound.INCLUSIVE) {
                  multiset = multiset.tailMultiset(firstInclusive, BoundType.CLOSED);

    assertEquals(ImmutableMap.of("google", googleValues, "foo", fooValues), asMap.headMap("h"));
    assertEquals(ImmutableMap.of("google", googleValues), asMap.subMap("g", "h"));
  }

  public void testTailSetClear() {
    TreeMultimap<String, Integer> multimap = TreeMultimap.create();
    multimap.put("a", 1);
    multimap.put("a", 11);
    multimap.put("b", 2);

   * Compares strings in natural order except that null comes immediately before a given value. This
   * works better than Ordering.natural().nullsFirst() because, if null comes before all other
   * values, it lies outside the submap/submultiset ranges we test, and the variety of tests that
   * exercise null handling fail on those subcollections.
   */
  public abstract static class NullsBefore implements Comparator<@Nullable String>, Serializable {

        putRangeMapEntry(
            rangeToRemove.upperBound,
            rangeMapEntry.getUpperBound(),
            mapEntryAboveToTruncate.getValue().getValue());
      }
    }
    entriesByLowerBound.subMap(rangeToRemove.lowerBound, rangeToRemove.upperBound).clear();
  }

  @Override
  public Map<Range<K>, V> asMapOfRanges() {
    return new AsMapOfRanges(entriesByLowerBound.values());
  }

  @Override