// use this package rn-fetch-blob
requestToPermissions = async () => {
    try {
      const granted = await PermissionsAndroid.request(
        PermissionsAndroid.PERMISSIONS.WRITE_EXTERNAL_STORAGE,
        {
          title: 'Music',
          message:
            'App needs access to your Files... ',
          buttonNeutral: 'Ask Me Later',
          buttonNegative: 'Cancel',
          buttonPositive: 'OK',
        },
      );
      if (granted === PermissionsAndroid.RESULTS.GRANTED) {
        console.log('startDownload...');
        this.startDownload();
      }
    } catch (err) {
      console.log(err);
    }
  };


startDownload = () => {
    const {tunes, token, currentTrackIndex} = this.state;
    let {url, name} = tunes[currentTrackIndex];
    RNFetchBlob.config({
      fileCache: true,
      appendExt: 'mp3',
      addAndroidDownloads: {
        useDownloadManager: true,
        notification: true,
        title: name,
        path: RNFetchBlob.fs.dirs.DownloadDir + `${name}`, // Android platform
        description: 'Downloading the file',
      },
    })
      .fetch('GET', url)
      .then(res => {
        console.log('res', res);
        console.log('The file is save to ', res.path());
      });
  };