How to use the @scion/microfrontend-platform.MessageHeaders.ReplyTo function in @scion/microfrontend-platform

mergeMap((request: TopicMessage) => {
          const manifestRegistry = Beans.get(ManifestRegistry);
          const replyTo = request.headers.get(MessageHeaders.ReplyTo);
          const appSymbolicName = request.headers.get(MessageHeaders.AppSymbolicName);

          return merge(of(null), manifestRegistry.capabilityChange$)
            .pipe(
              map(() => manifestRegistry.getCapabilitiesByApplication(appSymbolicName)),
              switchMap(capabilities => Beans.get(MessageClient).publish$(replyTo, capabilities)),
              takeUntilUnsubscribe(replyTo),
            );
        }),
        takeUntil(this._destroy$),

.pipe(mergeMap((request: TopicMessage) => {
          const manifestRegistry = Beans.get(ManifestRegistry);
          const replyTo = request.headers.get(MessageHeaders.ReplyTo);
          const appSymbolicName = request.headers.get(MessageHeaders.AppSymbolicName);

          return merge(of(null), manifestRegistry.intentChange$)
            .pipe(
              map(() => manifestRegistry.getIntentsByApplication(appSymbolicName)),
              switchMap(intents => Beans.get(MessageClient).publish$(replyTo, intents)),
              takeUntilUnsubscribe(replyTo),
            );
        }),
        takeUntil(this._destroy$),