How to use the ionic-native.AppVersion.getVersionCode function in ionic-native

AppVersion.getPackageName().then((value) => {
      this.appPackageName = value;
      console.log(value);
    }, (error) => {
      console.error(error);
    })

    AppVersion.getAppName().then((value) => {
      this.appName = value;
      console.log(value);
    }, (error) => {
      console.error(error);
    })

    AppVersion.getVersionCode().then((value) => {
      this.appVersionCode = value;
      console.log(value);
    }, (error) => {
      console.error(error);
    })
  }

output();
        }, ()=>output());

        AppVersion.getPackageName().then((data) => {
            _resolved_count++;
            package_name = data;
            output();
        }, ()=>output());

        AppVersion.getVersionNumber().then(data=>{
            _resolved_count++;
            version_number = data;
            output();
        }, ()=>output());

        AppVersion.getVersionCode().then(data=>{
            _resolved_count++;
            version_code = data;
            output();
        }, ()=>output());

    }