* 增量添加单词到词典中 * lazy update: 当用到词典的时候才重新build * 当新添加的词导致词典大小超出限制时,打印一个warning Update Vocabulary: * More words can be added after the building. * Lazy update: rebuild automatically when vocab is used. * print warning when max size is reached
* remove and fix other unit tests * add more code comments