src/vs/workbench/contrib/markers/browser/markersTreeViewer.ts/ResourceDragAndDrop/onDragStart
class ResourceDragAndDrop:	onDragStart(data: IDragAndDropData, originalEvent: DragEvent): void {
		const elements = (data as ElementsDragAndDropData<MarkerElement>).elements;
		const resources = elements
			.filter(e => e instanceof ResourceMarkers)
			.map(resourceMarker => (resourceMarker as ResourceMarkers).resource);

		if (resources.length) {
			// Apply some datatransfer types to allow for dragging the element outside of the application
			this.instantiationService.invokeFunction(accessor => fillEditorsDragData(accessor, resources, originalEvent));
		}
	}