Clear shapes after clearing an presentation

bigbluebutton-html5/imports/api/slides/server/modifiers/clearSlidesPresentation.js

 import Slides from '/imports/api/slides';
 import Logger from '/imports/startup/server/logger';
 import { check } from 'meteor/check';
+import clearShapesWhiteboard from '/imports/api/shapes/server/modifiers/clearShapesWhiteboard';
 
 export default function clearSlidesPresentation(meetingId, presentationId) {
   check(meetingId, String);
@@ -11,12 +12,18 @@ export default function clearSlidesPresentation(meetingId, presentationId) {
     presentationId,
   };
 
-  const cb = (err) => {
+  const whiteboardIds = Slides.find(selector).map(row => row.slide.id);
+
+  const cb = (err, numChanged) => {
     if (err) {
       return Logger.error(`Removing Slides from collection: ${err}`);
     }
 
-    return Logger.info(`Removed Slides where presentationId=${presentationId}`);
+    if (numChanged) {
+      whiteboardIds.forEach(whiteboardId => clearShapesWhiteboard(meetingId, whiteboardId));
+
+      return Logger.info(`Removed Slides where presentationId=${presentationId}`);
+    }
   };
 
   return Slides.remove(selector, cb);