UP-4177 refactor : idiomatic Groovy forEach
UP-4177 TestDox-style unit test method name.

JavaDoc documenting what is being tested.
UP-4177 assertEquals with message rather than assert keyword
UP-4177 Test the entire resulting attribute map and not just size.
UP-4177  When keyToDuplicate not found return existing attributes map unchanged.
Merge pull request #412 from apetro/UP-4177

UP-4177 When attribute to duplicate is missing, no-op.