code: @SuppressWarnings("unused")
    public String toJson() {
      Gson gson = new GsonBuilder()
        .registerTypeAdapterFactory(GeocodingAdapterFactory.create())
        .create();
      return gson.toJson(this);
    }
docs: This takes the currently defined values found inside this instance and converts it to a JSON
  string.
  
  @return a JSON string which represents this CarmenContext
  @since 3.0.0