added some possibilities for customizing the Map implementation
added some possibilities for customizing the Map implementation

evertrue/cglib,wangf111/cglib,292388900/cglib,mcculls/cglib,yseasony/cglib,TopicusZorg/cglib,baishuo/cglib,ligzy/cglib,xgbj/cglib,mohanaraosv/cglib,lukesandberg/cglib,mcmakev/cglib,liuyb02/cglib,HubSpot/cglib,chuz/cglib,cglib/cglib,lncosie/cglib