text: const Shotstack = require('shotstack-sdk');
  
  module.exports = (tracks, soundtrack = null, background = null, fonts = null) => {
      let timeline = new Shotstack.Timeline;
      timeline
          .setFonts(fonts)
          .setBackground(background)
          .setSoundtrack(soundtrack)
          .setTracks(tracks);
  
      return timeline;
  }
  