code: private boolean checkSupertypes(Class<?> cls) {
      for(Class<?> c : knownParameterizables) {
        if(c.isAssignableFrom(cls)) {
          return true;
        }
      }
      return false;
    }
docs: Check all supertypes of a class.
  
  @param cls Class to check.
  @return {@code true} when at least one supertype is a known parameterizable
  type.