The Sauce JUnit helper libraries help customers get set up with a way to run Parallel tests coming from different classes and Suites.
The implementation is heavily bases on JUnit's own Suite and Parametrized classes but tweak in certain ways to support a specific type of injection which involves injecting through the constructor method.
While this might work, it makes it hard to invoke a constructor on each sub-class of the Base class that implements the SuiteRunner class.
ConcurrentParametrized class that implements the Suite Runner class (link).
Example of a TestBase where this is being used (link).