src/vs/workbench/browser/parts/views/treeView.ts/CustomTreeViewDragAndDrop/addExtensionProvidedTransferTypes
class CustomTreeViewDragAndDrop:	private addExtensionProvidedTransferTypes(originalEvent: DragEvent, itemHandles: string[]) {
		if (!originalEvent.dataTransfer || !this.dndController) {
			return;
		}
		const uuid = generateUuid();

		this.dragCancellationToken = new CancellationTokenSource();
		this.treeViewsDragAndDropService.addDragOperationTransfer(uuid, this.handleDragAndLog(this.dndController, itemHandles, uuid, this.dragCancellationToken.token));
		this.treeItemsTransfer.setData([new DraggedTreeItemsIdentifier(uuid)], DraggedTreeItemsIdentifier.prototype);
		if (this.dndController.dragMimeTypes.find((element) => element === Mimes.uriList)) {
			// Add the type that the editor knows
			originalEvent.dataTransfer?.setData(DataTransfers.RESOURCES, '');
		}
		this.dndController.dragMimeTypes.forEach(supportedType => {
			originalEvent.dataTransfer?.setData(supportedType, '');
		});
	}