docs: private int calculateLevel() {
          int level = Integer.MIN_VALUE;
          Class<?> sclass = this.derived.getSuperclass();
          int idx = 0;
          while (!sclass.equals(Object.class)) {
              idx += 1;
              if (sclass.equals(this.base)) {
                  level = idx;
                  break;
              }
              sclass = sclass.getSuperclass();
          }
          return level;
      }