###

    SheetJS Firebase Dump Demo
    Example Code

      /* ... connect to firebase */
      const database = firebase.database();

      /* import workbook */
      await database.ref('foo').set(workbook);

      /* change cells */
      database.ref('foo').update({
        "Sheets/Sheet1/A1": {"t": "s", "v": "J"},
        "Sheets/Sheet1/A2": {"t": "n", "v": 5},
      });

      /* export snapshot */
      const val = await database.ref('foo').once('value').val();
      XLSX.writeFile(wb, "firebase.xlsx");