question: public static void toDo ( @ Scope int scope , String tag ) { List < Long > tagSeenList = tagLastSeenMap . get ( tag ) ; if ( tagSeenList . isEmpty ( ) ) { toDoSet . put ( tag ) ; return ; } Long tagLastSeen = tagSeenList . get ( tagSeenList . size ( ) - 1 ) ; if ( scope == THIS_APP_VERSION && tagLastSeen <= lastAppUpdatedTime ) { toDoSet . put ( tag ) ; } }
target:  Mark a tag as 'to do' within a given scope, if it has already marked to do or been done within that scope then it will not be marked.