Changes

This is the method that the engine will call the first time it syncs, in order to get a complete inventory of what data there is that will need to be uploaded to the server. Unless the items you're syncing have their own inherent GUIDs already defined, you'll need to invent GUIDs for all your items at this time. When one of these GUIDs is later passed as an argument to <tt>createRecord()</tt>, you need to return a record based on the matching data. Therefore, it's the responsibility of this method to define the guid -> item mapping, and to store it for later reference by other methods.

=== wipe() ===