assertEquals(ImmutableSortedMap.of(2, 0), Maps.subMap(map, Range.open(0, 4)));
    assertEquals(ImmutableSortedMap.of(4, 0), Maps.subMap(map, Range.open(2, 6)));
    assertEquals(ImmutableSortedMap.of(4, 0, 6, 0), Maps.subMap(map, Range.open(3, 7)));
    assertEquals(empty, Maps.subMap(map, Range.open(20, 30)));

    assertEquals(map, Maps.subMap(map, Range.openClosed(0, 12)));

    /**
     * Usually the same as map, but smaller for the headMap(), tailMap(), or subMap() of a
     * SortedAsMap.
     */
    final transient Map<K, Collection<V>> submap;

    AsMap(Map<K, Collection<V>> submap) {
      this.submap = submap;
    }

    @Override
    protected Set<Entry<K, Collection<V>>> createEntrySet() {
      return new AsMapEntries();

    assertEquals(ImmutableSortedMap.of(2, 0), Maps.subMap(map, Range.open(0, 4)));
    assertEquals(ImmutableSortedMap.of(4, 0), Maps.subMap(map, Range.open(2, 6)));
    assertEquals(ImmutableSortedMap.of(4, 0, 6, 0), Maps.subMap(map, Range.open(3, 7)));
    assertEquals(empty, Maps.subMap(map, Range.open(20, 30)));

    assertEquals(map, Maps.subMap(map, Range.openClosed(0, 12)));

      } else if (from == Bound.EXCLUSIVE && to == Bound.EXCLUSIVE) {
        return map.subMap(firstExclusive, false, lastExclusive, false);
      } else if (from == Bound.EXCLUSIVE && to == Bound.INCLUSIVE) {
        return map.subMap(firstExclusive, false, lastInclusive, true);
      } else if (from == Bound.INCLUSIVE && to == Bound.INCLUSIVE) {
        return map.subMap(firstInclusive, true, lastInclusive, true);
      } else {

  }

  @Override
  public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
    return new SafeTreeMap<>(
        delegate.subMap(checkValid(fromKey), fromInclusive, checkValid(toKey), toInclusive));
  }

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

  @Override

  }

  @Override
  @ParametricNullness
  public K lastKey() {
    return delegate().lastKey();
  }

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

  @Override
  public SortedMap<K, V> tailMap(@ParametricNullness K fromKey) {
    return delegate().tailMap(fromKey);
  }

  /**

      } else if (from == Bound.EXCLUSIVE && to == Bound.EXCLUSIVE) {
        return map.subMap(firstExclusive, false, lastExclusive, false);
      } else if (from == Bound.EXCLUSIVE && to == Bound.INCLUSIVE) {
        return map.subMap(firstExclusive, false, lastInclusive, true);
      } else if (from == Bound.INCLUSIVE && to == Bound.INCLUSIVE) {
        return map.subMap(firstInclusive, true, lastInclusive, true);
      } else {

  }

  @Override
  public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
    return new SafeTreeMap<>(
        delegate.subMap(checkValid(fromKey), fromInclusive, checkValid(toKey), toInclusive));
  }

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

  @Override

    @Override
    public NavigableMap<K, V2> subMap(
        @ParametricNullness K fromKey,
        boolean fromInclusive,
        @ParametricNullness K toKey,
        boolean toInclusive) {
      return transformEntries(
          fromMap().subMap(fromKey, fromInclusive, toKey, toInclusive), transformer);
    }

    @Override

    @Override
    public NavigableMap<K, V2> subMap(
        @ParametricNullness K fromKey,
        boolean fromInclusive,
        @ParametricNullness K toKey,
        boolean toInclusive) {
      return transformEntries(
          fromMap().subMap(fromKey, fromInclusive, toKey, toInclusive), transformer);
    }

    @Override