code: @Override
      public void visitClassContext(ClassContext context) {
          JavaClass cls = context.getJavaClass();
          if (!isInternal(cls.getClassName())) {
              ConstantPool pool = cls.getConstantPool();
              int numItems = pool.getLength();
              for (int i = 0; i < numItems; i++) {
                  Constant c = pool.getConstant(i);
                  if (c instanceof ConstantClass) {
                      String clsName = ((ConstantClass) c).getBytes(pool);
                      if (isInternal(clsName)) {
                          bugReporter.reportBug(
                                  new BugInstance(this, BugType.IICU_INCORRECT_INTERNAL_CLASS_USE.name(), NORMAL_PRIORITY).addClass(cls).addString(clsName));
                      }
                  }
              }
          }
      }
docs: implements the visitor to look for classes that reference com.sun.xxx, or org.apache.xerces.xxx classes by looking for class Const in the constant pool
  
  @param context
  the context object of the currently parsed class