code: @Override
      public boolean addTransformer(final ClassFileTransformer cft) {
          boolean added = false;
          for (ClassLoader loader : followOnClassLoaders) {
              if (loader instanceof SpringLoader) {
                  added |= ((SpringLoader) loader).addTransformer(cft);
              }
          }
          return added;
      }
docs: Spring to register the given ClassFileTransformer on this ClassLoader