docs: function addonsManager_getAddonLink(aSpec) {
      var spec = aSpec || { };
      var addon = spec.addon;
      var link = spec.link;
  
      if (!link)
        throw new Error(arguments.callee.name + ": Link not specified.");
  
      return this.getAddonChildElement({addon: addon, type: link + "Link"});
    }