code: @Override
    protected String getCommonSuperClass(final String type1, final String type2) {
      try {
        ClassNode info1 = typeInfo(type1);
        ClassNode info2 = typeInfo(type2);
        if ((info1.access & Opcodes.ACC_INTERFACE) != 0) {
          if (typeImplements(type2, info2, type1)) {
            return type1;
          }
          if ((info2.access & Opcodes.ACC_INTERFACE) != 0) {
            if (typeImplements(type1, info1, type2)) {
              return type2;
            }
          }
          return "java/lang/Object";
        }
        if ((info2.access & Opcodes.ACC_INTERFACE) != 0) {
          if (typeImplements(type1, info1, type2)) {
            return type2;
          } else {
            return "java/lang/Object";
          }
        }
        String b1 = typeAncestors(type1, info1);
        String b2 = typeAncestors(type2, info2);
        String result = "java/lang/Object";
        int end1 = b1.length();
        int end2 = b2.length();
        while (true) {
          int start1 = b1.lastIndexOf(';', end1 - 1);
          int start2 = b2.lastIndexOf(';', end2 - 1);
          if (start1 != -1 && start2 != -1
              && end1 - start1 == end2 - start2) {
            String p1 = b1.substring(start1 + 1, end1);
            String p2 = b2.substring(start2 + 1, end2);
            if (p1.equals(p2)) {
              result = p1;
              end1 = start1;
              end2 = start2;
            } else {
              return result;
            }
          } else {
            return result;
          }
        }
      } catch (ClassNotFoundException e) {
        return "java/lang/Object"; // Handle classes that may be obfuscated
      }
    }
docs: Returns the common super type of the two given types without actually loading
  the classes in the ClassLoader.