docs: void addSuperclass(final String superclassName, final Map<String, ClassInfo> classNameToClassInfo) {
          if (superclassName != null && !superclassName.equals("java.lang.Object")) {
              final ClassInfo superclassClassInfo = getOrCreateClassInfo(superclassName, /* classModifiers = */ 0,
                      classNameToClassInfo);
              this.addRelatedClass(RelType.SUPERCLASSES, superclassClassInfo);
              superclassClassInfo.addRelatedClass(RelType.SUBCLASSES, this);
          }
      }