code: function makeBookmarkedTabItem(bm) {
    var urlStr = bm.url;
    if (!urlStr) {
      console.error('makeBookmarkedTabItem: Malformed bookmark: missing URL!: ', bm);
      urlStr = ''; // better than null or undefined!
    }
  
    if (bm.title === undefined) {
      console.warn('makeBookmarkedTabItem: Bookmark title undefined (ignoring...): ', bm);
    }
  
    var tabItem = new TabItem({
      url: urlStr,
  
      saved: true,
      savedTitle: _.get(bm, 'title', urlStr),
  
      savedBookmarkId: bm.id,
      savedBookmarkIndex: bm.index
    });
  
    return tabItem;
  }
docs: Initialize a TabItem from a bookmark
  
  Returned TabItem is closed (not associated with an open tab)