docstrings
example
Method get_data() should be part of the BaseHandler. It is generic enough. The other 2 methods, get_data_item() and get_data_set() are handler specific, but also relevant for the BaseHandler
Method BaseHandler.is_catastrophic() is invoked by get_data() and makes the necessary checks for plural GET or DELETE actions
And the corresponding tests for method is_catastrophic()
Expanding the testproject.testapp with another model
And the corresponding handler