code: function PaymentRequest(options) {
    if (!(this instanceof PaymentRequest))
      return new PaymentRequest(options);
  
    this.version = -1;
    this.pkiType = null;
    this.pkiData = null;
    this.paymentDetails = new PaymentDetails();
    this.signature = null;
  
    if (options)
      this.fromOptions(options);
  }
docs: Represents a BIP70 payment request.
  @alias module:bip70.PaymentRequest
  @constructor
  @param {Object?} options
  @property {Number} version
  @property {String|null} pkiType
  @property {Buffer|null} pkiData
  @property {PaymentDetails} paymentDetails
  @property {Buffer|null} signature