Added ability to do manual stacking

Author: adamzolotarev

Source/Shared/Extensions/EventBuilderExtensions.cs

@@ -54,5 +54,16 @@ public static EventBuilder SetVersion(this EventBuilder builder, string version)
             builder.Target.SetVersion(version);
             return builder;
         }
+
+        /// <summary>
+        /// Changes default stacking behavior by setting the stacking key.
+        /// </summary>
+        /// <param name="builder">The event builder object.</param>
+        /// <param name="stackingKey">The manual stacking key.</param>
+        public static EventBuilder SetManualStackingKey(this EventBuilder builder, string manualStackingKey)
+        {
+            builder.Target.SetManualStackingKey(manualStackingKey);
+            return builder;
+        }
     }
 }

Source/Shared/Extensions/EventExtensions.cs

@@ -211,6 +211,19 @@ public static void SetUserDescription(this Event ev, UserDescription description
 
             ev.Data[Event.KnownDataKeys.UserDescription] = description;
         }
+
+        /// <summary>
+        /// Sets the manual stacking key
+        /// </summary>
+        /// <param name="ev">The event</param>
+        /// <param name="manualStackingKey">The manual stacking key.</param>
+        public static void SetManualStackingKey(this Event ev, string manualStackingKey)
+        {
+            if (String.IsNullOrWhiteSpace(manualStackingKey))
+                return;
+
+            ev.Data[Event.KnownDataKeys.ManualStackingKey] = manualStackingKey.Trim();
+        }
     }
 
     /// <summary>
@@ -245,5 +258,10 @@ public ExtendedDataInfo() {
         /// Specifies if properties that throw serialization errors should be ignored.
         /// </summary>
         public bool IgnoreSerializationErrors { get; set; }
+
+        /// <summary>
+        /// Overrided defalut stacking behavior.
+        /// </summary>
+        public string StackingKey { get; set; }
     }
 }

Source/Shared/Models/Client/Event.cs

@@ -78,6 +78,7 @@ public static class KnownDataKeys {
             public const string Version = "@version";
             public const string Level = "@level";
             public const string SubmissionMethod = "@submission_method";
+            public const string ManualStackingKey = "@manual_stacking_key";
         }
     }
 }