Fixed Issue #4: Changed function iCustom to use request/respons pattern.

MtApi/Responses/ICustomResponse.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MtApi.Responses
+{
+    public class ICustomResponse: ResponseBase
+    {
+        public double Value { get; set; }
+    }
+}