如何在Guava Multi Map

Question

我想删除内部多图“car_model_id”中的特定键，其中包含 DetailClass 中包含的字符值'Y' s实例变量“flag”通过外部地图键查询。

   // Outermap:
   Multimap<Long, Multimap<Integer, DetailClass>> car_manufacturer_id = ArrayListMultimap.create();

   // Innermap:
   Multimap<Integer, DetailClass> car_model_id = ArrayListMultimap.create();

   // DetailClass instance variables
   attr_key, serial, flag, state

   // Inserting Values to Inner Map
    car_model_id.put(1, new DetailClass(1016,'PO-90','Y',"TX"));
    car_model_id.put(1, new DetailClass(1011,'PO-90','N',"TX"));
    car_model_id.put(1, new DetailClass(1022,'PO-90','Y',"LA"));

    car_model_id.put(2, new DetailClass(1016,'PO-80','Y',"RE"));
    car_model_id.put(2, new DetailClass(1011,'PO-80','N',"GA"));
    car_model_id.put(2, new DetailClass(1022,'PO-80','N',"NY"));

   car_manufacturer_id.put((long) 501747, car_model_id);