/// <summary>
 /// Construct the API method instance.
 /// </summary>
 /// <param name="rublon">Rublon instance.</param>
 /// <param name="callbackUrl">URL of the callback method.</param>
 /// <param name="userEmail">User's email address.</param>
 /// <param name="userId">User's local ID.</param>
 /// <param name="consumerParams">Additional transaction parameters.</param>
 public BeginTransaction(Rublon rublon, string callbackUrl, string userEmail, string userId, JObject consumerParams)
     : base(rublon)
 {
     this.callbackUrl    = callbackUrl;
     this.userEmail      = userEmail;
     this.userId         = userId;
     this.consumerParams = consumerParams;
 }
 /// <summary>
 /// Construct the API method instance.
 /// </summary>
 /// <param name="rublon">Rublon instance.</param>
 /// <param name="callbackUrl">URL of the callback method.</param>
 /// <param name="userEmail">User's email address.</param>
 /// <param name="userId">User's local ID.</param>
 public BeginTransaction(Rublon rublon, string callbackUrl, string userEmail, string userId)
     : this(rublon, callbackUrl, userEmail, userId, new JObject())
 {
 }
 public RublonCallback(Rublon rublon)
     : base(rublon)
 {
     this.rublon = rublon;
 }