Android的AccountManager的hasFeatures方法的
API documentation具有以下关于每个验证器支持哪些功能的说明：
Account features are authenticator-specific string tokens identifying
boolean account properties. For example,features are used to tell
whether Google accounts have a particular service (such as Google
Calendar or Google Talk) enabled. The feature names and their meanings
are published somewhere associated with the authenticator in question.
解决方法
我还没有找到任何官方文档,但我已经找出了主要用例,即确定Google帐户是否与特定Google服务相关联.
每项服务都有一项功能,功能名称的格式为service_< service_code_name>.使用this (possibly out-of-date) list of service code names for Google服务,我们可以检查service_lh2(Picasa),service_groups2(Google网上论坛)和service_mail(GMail)等功能.
