just before adding authorization service.
[photos] / src / main / java / org / wamblee / photos / concurrent /
drwxr-xr-x   ..
-rw-r--r-- 4603 ConcurrentAlbum.java
-rw-r--r-- 1673 ConcurrentPhoto.java
-rw-r--r-- 2102 ConcurrentPhotoEntry.java