private static boolean isClassOfInterest(Class<?> c, Class<?> searchClass) {
        boolean isAbstract = Modifier.isAbstract(c.getModifiers());
        return searchClass.isAssignableFrom(c) && !isAbstract;
    }
Return true if c is a derivative of the filter class 
and is not abstract.
Ghidra/Framework/Generic/src/main/java/ghidra/util/TestSuiteUtilities.java