src/vs/workbench/contrib/notebook/browser/services/notebookWorkerServiceImpl.ts/NotebookWorkerClient/computeDiff
class NotebookWorkerClient:	computeDiff(original: URI, modified: URI) {
		return this._withSyncedResources([original, modified]).then(proxy => {
			return proxy.computeDiff(original.toString(), modified.toString());
		});
	}