it would be helpful if there is a page with which the developer can see what is the current content of the file where the pages for specific session are stored.
This way she can follow what has been stored, how many bytes were written so far, speculate when a page is going to be dropped/expired, etc.
The page will be in wicket-devutils package and will either auto-mount itself at some predefined path (e.g. /wicket/internal/debug/diskDataStore) or will be reachable via BookmarkableMapper (i.e. /wicket/bookmarkable/org.apache.wicket.devutils.diskpagestore.DebugPage).
Additionally to be able to extract the needed information a custom DiskDataStore will be plugged when devutils are enabled. This custom data store extends the default (DiskDataStore) to expose some hidden knowledge and to provide more debug information.