return Promise.reject<any>(errors.canceled());
}
const serializedRequestArguments = MessageIO.serializeRequestArguments(args, this._uriReplacer);
const req = ++this._lastMessageId;
const callId = String(req);
const result = new LazyPromise();
const disposable = new DisposableStore();
if (cancellationToken) {
disposable.add(cancellationToken.onCancellationRequested(() => {
const msg = MessageIO.serializeCancel(req);