/**
   * JSON fragment representation of this object
   *
   * @return JSON fragment for this object. Name for outer object expected to be set by calling
   *     method. This fragment returns inner properties representation only
   */
  protected String toJSONFragment() {
    StringBuffer json = new StringBuffer();
    boolean first = true;
    if (isSetAllOfferListingsConsidered()) {
      if (!first) json.append(", ");
      json.append(quoteJSON("AllOfferListingsConsidered"));
      json.append(" : ");
      json.append(quoteJSON(isAllOfferListingsConsidered() + ""));
      first = false;
    }
    if (isSetProduct()) {
      if (!first) json.append(", ");
      json.append("\"Product\" : {");
      Product product = getProduct();

      json.append(product.toJSONFragment());
      json.append("}");
      first = false;
    }
    if (isSetError()) {
      if (!first) json.append(", ");
      json.append("\"Error\" : {");
      Error error = getError();

      json.append(error.toJSONFragment());
      json.append("}");
      first = false;
    }
    return json.toString();
  }