docs: public ClassInfoList getSuperclasses(final String subclassName) {
          if (closed.get()) {
              throw new IllegalArgumentException("Cannot use a ScanResult after it has been closed");
          }
          if (!scanSpec.enableClassInfo) {
              throw new IllegalArgumentException("Please call ClassGraph#enableClassInfo() before #scan()");
          }
          final ClassInfo subclass = classNameToClassInfo.get(subclassName);
          return subclass == null ? ClassInfoList.EMPTY_LIST : subclass.getSuperclasses();
      }