SHK-4494: Null check for insert notification method

Author: Mislav Stanić

src/builders/NotificationEventBuilder.js

@@ -30,6 +30,9 @@ class NotificationEventBuilder {
 
     setId(value) {
         this._id = value;
+        if (!this._id) {
+            this._id = '';
+        }
         return this;
     }
 
@@ -39,6 +42,9 @@ class NotificationEventBuilder {
 
     setTitle(value) {
         this._title = value;
+        if (!this._title) {
+            this._title = '';
+        }
         return this;
     }
 
@@ -48,6 +54,9 @@ class NotificationEventBuilder {
 
     setDescription(value) {
         this._description = value;
+        if (!this._description) {
+            this._description = '';
+        }
         return this;
     }