public static void process(@NonNull final Activity activity, final String progressTitle, final Func1<Consumer<FolderProcessStatus>, FolderProcessResult> process, final Consumer<FolderProcessResult> callback) {
            new FolderProcessTask(activity, progressTitle, process, callback).execute();
        }
Returns a pair of longs where left one is free space in bytes and right one is number of files
main/src/main/java/cgeo/geocaching/storage/FolderUtils.java