I bumped into ClassTestCase for the first time, with class comment... "This class is intended for unit tests of individual classes and their metaclasses. It provides methods to determine the coverage of the unit tests. Subclasses are expected to re-implement: #classesToBeTested and #selectorsToBeIgnored. They should also implement to confirm that all methods have been tested. #testCoverage super testCoverage. " A few questions to improve my knowledge of how to use this... a. there are no implementors of #classesToBeTested but several of #classToBeTested. I presume the class comment is wrong? b. there are no implementors of #testCoverage, so I presume I can ignore that? (and I've no example to work from) c. ClassTestCase is subclassed 73 times, but #selectorsToBeIgnored is only implemented 9 times. So this seems not critical? But btw, every of those at least ignores #printOn:. I'm curious why? These are tagged "private", but is that a good reason not to test it? My purpose was to add a new class MagnitudeTest for a new new method to Magnitude in response to the recent #min:max: discussion. cheers -ben