= P extends null ? P | undefined : P;
export type HandlerResult {
(params: P, token: CancellationToken): HandlerResult {
(params: P): NotificationResult;
}
export interface NotificationHandler1 (type: RequestType , params: NoInfer (type: RequestType , handler: NoInfer (type: NotificationType , params?: NoInfer (type: NotificationType , handler: NoInfer