code: public void fromJson(JSONObject json) {
          super.fromJson(json);
          if (json.containsKey(CHANGE)) {
              change = new Change(json.getJSONObject(CHANGE));
          }
          if (json.containsKey(PATCH_SET)) {
              patchSet = new PatchSet(json.getJSONObject(PATCH_SET));
          } else if (json.containsKey(PATCHSET)) {
              patchSet = new PatchSet(json.getJSONObject(PATCHSET));
          }
      }
docs: Takes a JSON object and fills its internal data-structure.
  
  @param json the JSON Object.