doc

js/common/view/ElectromagnetNode.ts

@@ -105,6 +105,7 @@ export default class ElectromagnetNode extends FELMovableNode {
         this.cursor = ( dragEnabled && inputEnabled ) ? 'pointer' : null;
       } );
 
+    // Because backgroundNode is added to the scene graph elsewhere, ensure that it is draggable only if this Node is draggable.
     this.inputEnabledProperty.link( inputEnabled => {
       this.backgroundNode.inputEnabledProperty.value = inputEnabled;
     } );