docs: function addonsManager_isAddonCompatible(aSpec) {
      var spec = aSpec || { };
      var addon = spec.addon;
  
      if (!addon)
        throw new Error(arguments.callee.name + ": Add-on not specified.");
  
      // XXX: Bug 599702 doens't give enough information which type of notification
      return addon.getNode().getAttribute("notification") != "warning";
    }