.hashSetValues()
            .<String, Integer>build();
  }

  @J2ktIncompatible
  @GwtIncompatible // doesn't build without explicit type parameters on build() methods
  public void testTreeKeys() {
    ListMultimap<String, Integer> multimap = MultimapBuilder.treeKeys().arrayListValues().build();
    assertTrue(multimap.keySet() instanceof SortedSet);
    assertTrue(multimap.asMap() instanceof SortedMap);
  }