assertEqualInOrder(
            entries.subList(i, j),
            navigableMap.subMap(entries.get(i).getKey(), entries.get(j).getKey()).entrySet());
      }
    }
  }

  @CollectionSize.Require(SEVERAL)
  public void testSubMapIllegal() {
    assertThrows(IllegalArgumentException.class, () -> navigableMap.subMap(c.getKey(), a.getKey()));
  }

  @CollectionSize.Require(absent = ZERO)

    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);
  }

  @Override
  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);

    @Override
    public NavigableMap<K, V> subMap(
        K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
      synchronized (mutex) {
        return navigableMap(delegate().subMap(fromKey, fromInclusive, toKey, toInclusive), mutex);
      }
    }

    @Override
    public SortedMap<K, V> subMap(K fromKey, K toKey) {
      return subMap(fromKey, true, toKey, false);
    }

    @Override
    public NavigableMap<K, V> subMap(
        K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
      synchronized (mutex) {
        return navigableMap(delegate().subMap(fromKey, fromInclusive, toKey, toInclusive), mutex);
      }
    }

    @Override
    public SortedMap<K, V> subMap(K fromKey, K toKey) {
      return subMap(fromKey, true, toKey, false);
    }

    public void clear() {
      standardClear();
    }

    @Override
    public boolean isEmpty() {
      return standardIsEmpty();
    }

    @Override
    public SortedMap<K, V> subMap(K fromKey, K toKey) {
      return standardSubMap(fromKey, toKey);
    }

    @Override
    public @Nullable Entry<K, V> lowerEntry(K key) {
      return standardLowerEntry(key);
    }

    @Override

   * 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();
  }

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

        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

                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);