refactor(IAssistant): Removed unused Assistant interface

Author: mediumTaj

Scripts/Services/Assistant/v1/Assistant.cs

@@ -26,7 +26,7 @@
 
 namespace IBM.Watson.DeveloperCloud.Services.Assistant.v1
 {
-    public class Assistant : IWatsonService, IAssistant
+    public class Assistant : IWatsonService
     {
         private const string ServiceId = "Assistantv1";
         private fsSerializer _serializer = new fsSerializer();
@@ -68,6 +68,23 @@ public string VersionDate
             set { _versionDate = value; }
         }
 
+        #region Callback delegates
+        /// <summary>
+        /// Success callback delegate.
+        /// </summary>
+        /// <typeparam name="T">Type of the returned object.</typeparam>
+        /// <param name="response">The returned object.</param>
+        /// <param name="customData">user defined custom data including raw json.</param>
+        public delegate void SuccessCallback<T>(T response, Dictionary<string, object> customData);
+
+        /// <summary>
+        /// Fail callback delegate.
+        /// </summary>
+        /// <param name="error">The error object.</param>
+        /// <param name="customData">User defined custom data</param>
+        public delegate void FailCallback(RESTConnector.Error error, Dictionary<string, object> customData);
+        #endregion
+
         /// <summary>
         /// Assistant constructor.
         /// </summary>