this.fileTransfer.download('https://github.com/janpio/ionic-epubjs/raw/master/src/assets/books/moby-dick.epub', path + 'moby-dick.epub').then(entry => {
      this.finishedDownload = true;
      let url = entry.toURL();
      this.current_book = new Book();
      this.current_book.label = "Moby Dick (.epub)";
      this.current_book.file =  path + 'moby-dick.epub';
    })