for (int i = 0; i < entries.size(); i++) {
      assertEqualInOrder(
          entries.subList(0, i), navigableMap.headMap(entries.get(i).getKey()).entrySet());
    }
  }

  public void testTailMap() {
    List<Entry<K, V>> entries =
        copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));