No constructor error for class::method arguments with baseless tests

[thekid]

$ xp test unittest.tests.AssertTest::values_equal_themselves
Uncaught exception: Exception lang.ElementNotFoundException (No constructor in class unittest.tests.AssertTest)
  at lang.XPClass::getConstructor() [line 33 of ClassSource.class.php]
  at xp.unittest.sources.ClassSource::provideTo(unittest.TestSuite{}, array[0]) [line 341 of TestRunner.class.php]
  at xp.unittest.TestRunner::run(array[1]) [line 368 of TestRunner.class.php]
  at xp.unittest.TestRunner::main(array[1]) [line 381 of class-main.php]