code: @Override
      public void visitClassContext(ClassContext classContext) {
          try {
              clsContext = classContext;
              JavaClass cls = classContext.getJavaClass();
              if (cls.isInterface())
                  return;
              superClasses = cls.getSuperClasses();
              cls.accept(this);
          } catch (ClassNotFoundException cnfe) {
              bugReporter.reportMissingClass(cnfe);
          } finally {
              clsContext = null;
              superClasses = null;
          }
      }
docs: implements the detector to collect the super classes
  
  @param classContext
  the context object for the currently parsed class