Remove dead & duplicated code (#11405)

* Remove dead code

* Make dead code happier

* DRY pickle additional data calculation

* Iterate

src/models/Call.ts

@@ -157,7 +157,7 @@ export abstract class Call extends TypedEventEmitter<CallEvent, CallEventHandler
         this.emit(CallEvent.Participants, value, prevValue);
     }
 
-    public constructor(
+    protected constructor(
         /**
          * The widget used to access this call.
          */