docs: function softwareUpdate_download(channel, waitForFinish, timeout) {
      waitForFinish = waitForFinish ? waitForFinish : true;
  
      // Check that the correct channel has been set
      this._controller.assert(function() {
        return channel == this.channel;
      }, "The current update channel is identical to the specified one.", this);
  
      // Click the next button
      var next = this.getElement({type: "button", subtype: "next"});
      this._controller.click(next);
  
      // Wait for the download page - if it fails the update was already cached
      try {
        this.waitForWizardPage(WIZARD_PAGES.downloading);
  
        if (waitForFinish)
          this.waitforDownloadFinished(timeout);
      } catch (ex) {
        this.waitForWizardPage(WIZARD_PAGES.finished);
      }
    }