Introduce a transformer that validates its input using Hamcrest.
Validate output using the same Hamcrest matcher.
Fixed the test, "a Rekord can store values using a transformed key and retrieve them without transformations".
Collectors!
Reorganize RekordTests.
Extract the six RekordTest subclasses into their own classes.
Move the test object classes into their own package.
Reorder imports.
Moar static imports.
A Rekord collector can take keys of the supertype.
Split collectors into accumulators and finishers.
Rename "RekordCollector" to "Kollector".
Remove redundant types in the Finisher.
Accumulators cannot be typed to the rekord type.