How to use the @qawolf/config.CONFIG.display function in @qawolf/config

// grab the X11 display
      "-f",
      "x11grab",
      // hide mouse
      "-draw_mouse",
      "0",
      // 20 fps
      "-framerate",
      "20",
      // record display size
      "-video_size",
      `${this._size.width}x${this._size.height}`,
      // input
      "-i",
      //:display+x,y offset
      `${CONFIG.display}+${this._offset.x},${this._offset.y}`,
      // overwrite output
      "-y",
      // balance high quality and good compression https://superuser.com/a/582327/856890
      "-vcodec",
      "libx264",
      "-pix_fmt",
      "yuv420p",
      "-crf",
      "19",
      "-preset",
      "slow",
      // mp4 plays well in browsers
      "-f",
      "mp4",
      this._videoPath
    ];