A Red-Black tree based NavigableMap implementation. The map is sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time, depending on which constructor is used.
    基于红黑树的NavigableMap实现。映射根据其键的自然顺序排序,或者根据在map创建时提供的比较器，具体取决于使用的构造函数。
    This implementation provides guaranteed log(n) time cost for the containsKey, get, put and remove operations. Algorithms are adaptations of those in Cormen, Leiserson, and Rivest’s Introduction to Algorithms.
    这个实现为containsKey,get,put和remove操作提供保证的log(n)时间复杂度。算法是对Cormen, Leiserson和Rivest的《算法导论》中那些算法的改编。

    Note that this implementation is not synchronized

    TreeSet与TreeMap和HashSet与HashMap的关系一样