How to use the @scion/workbench-application-platform.api.ManifestCommands.FindCapabilities function in @scion/workbench-application-platform

public capabilities$(type: string, qualifier: Qualifier): Observable {
    const intentMessage: ManifestRegistryIntentMessages.FindCapabilities = {
      type: PlatformCapabilityTypes.ManifestRegistry,
      qualifier: NilQualifier,
      payload: {
        command: ManifestCommands.FindCapabilities,
        type: type,
        qualifier: qualifier,
      },
    };

    return this._capabilityChange$
      .pipe(
        startWith(undefined as void),
        switchMap(() => Platform.getService(MessageBus).requestReceive$({channel: 'intent', message: intentMessage}, {once: true})),
        extractMessage([]),
      );
  }

this.queryManifest(envelope as MessageEnvelope);
        break;
      }
      case ManifestCommands.FindCapabilityProviders: {
        this.queryCapabilityProviders(envelope as MessageEnvelope);
        break;
      }
      case ManifestCommands.FindCapabilityConsumers: {
        this.queryCapabilityConsumers(envelope as MessageEnvelope);
        break;
      }
      case ManifestCommands.FindCapability: {
        this.queryCapability(envelope as MessageEnvelope);
        break;
      }
      case ManifestCommands.FindCapabilities: {
        this.queryCapabilities(envelope as MessageEnvelope);
        break;
      }
      case ManifestCommands.RegisterCapability: {
        this.registerCapability(envelope as MessageEnvelope);
        break;
      }
      case ManifestCommands.UnregisterCapability: {
        this.unregisterCapability(envelope as MessageEnvelope);
        break;
      }
      default: {
        this._logger.error(`[UnsupportedQueryError] Command not supported [command=${command}]`);
        this._messageBus.publishReply(null, envelope.sender, envelope.replyToUid);
      }
    }