code: function findTargetFromParentInfo(parentInfo=window.parentInfo) {
    if (!parentInfo) return null;
    if ('guestInstanceId' in parentInfo) {
      return require('electron').remote.getGuestWebContents(parentInfo.guestInstanceId);
    }
  
    if ('webContentsId' in parentInfo) {
      return webContents.fromId(parentInfo.webContentsId);
    }
  
    return null;
  }
docs: Given the parentInfo returned from {getSenderIdentifier}, returns the actual
  WebContents that it represents.
  
  @param  {object} parentInfo  The renderer process identifying info.
  
  @return {WebContents}        An actual Renderer Process object.
  
  @private