Investigating the effort it would take to upgrade Groovy from 2.4.12 to 2.4.21 so we don't lag too far behind upstream. This is probably safest route to go as going to 2.5 would introduce too many additional features that may not readily manifest itself, let alone resolve.

See the attached spreadsheet for a list of the new features/improvements/dependency upgrades from 2.4.12 to 2.4.21