docs: private static void addFrameOutput(FramingContext state, Object parent, String property,
              Object output) {
          if (parent instanceof Map) {
              List<Object> prop = (List<Object>) ((Map<String, Object>) parent).get(property);
              if (prop == null) {
                  prop = new ArrayList<Object>();
                  ((Map<String, Object>) parent).put(property, prop);
              }
              prop.add(output);
          } else {
              ((List) parent).add(output);
          }
      }