Adding Nadir method on timepointApi

Packages/ohif-viewerbase/client/components/viewer/imageViewerViewport/imageViewerViewport.js

@@ -468,7 +468,7 @@ const setDisplaySet = (data, displaySetInstanceUid, templateData) => {
         throw new OHIFError('Study does not exist');
     }
 
-    let displaySets = study.getDisplaySets();
+    let displaySets = study.displaySets;
     if (!displaySets.length) {
         displaySets = OHIF.viewerbase.sortingManager.getDisplaySets(study);
         study.displaySets = displaySets;