docs: private String getClassInfoNameOrClassName() {
          String className;
          ClassInfo ci = getClassInfo();
          if (ci == null) {
              ci = classInfo;
          }
          if (ci != null) {
              // Get class name from getClassInfo().getName() 
              className = ci.getName();
          } else {
              // Get class name from getClassName() 
              className = getClassName();
          }
          if (className == null) {
              throw new IllegalArgumentException("Class name is not set");
          }
          return className;
      }