Hi,
I implemented both create(String[]) and delete(int, long) in Data.java, but my UI does not use them at all.
Your data access class must be called Data.java, must be in a package called "suncertify.db", and MUST implement the following interface...
To me, this means that all the methods in the supplied interface must be implemented.
As far as the UI is concerned, I did not provide the ability to add/remove contractors. It is simply not in the specifications, and going beyond the requirements could be a bad thing.
Also, here is another possible justification for implementing create and delete in Data.java, even though these methods are never used by the UI. Perhaps, in the future, someone will want to write another program for an administrator to use to add and remove contractors from the database. This isn't necessarily something a customer service representative should be allowed to do. By implementing create and delete, this new program could simply use your Data class as it is.
Anyway, that's what I think. Hope this helped.