code: public ClassDoc[] ordinaryClasses() {
          ListBuffer<ClassDocImpl> ret = new ListBuffer<>();
          for (ClassDocImpl c : getClasses(true)) {
              if (c.isOrdinaryClass()) {
                  ret.append(c);
              }
          }
          return ret.toArray(new ClassDocImpl[ret.length()]);
      }
docs: Get ordinary classes (that is, exclude exceptions, errors,
  enums, interfaces, and annotation types) in this package.
  
  @return included ordinary classes in this package.