this.add("focus", "@mozilla.org/focus-manager;1", "nsIFocusManager");
this.add("history", "@mozilla.org/browser/global-history;2",
["nsIBrowserHistory", "nsIGlobalHistory3", "nsINavHistoryService", "nsPIPlacesDatabase"]);
this.add("io", "@mozilla.org/network/io-service;1", "nsIIOService");
this.add("json", "@mozilla.org/dom/json;1", "nsIJSON", "createInstance");
this.add("focus", "@mozilla.org/focus-manager;1", "nsIFocusManager");
this.add("history", "@mozilla.org/browser/global-history;2",
["nsIBrowserHistory", "nsIGlobalHistory3", "nsINavHistoryService", "nsPIPlacesDatabase"]);
this.add("io", "@mozilla.org/network/io-service;1", "nsIIOService");
this.add("json", "@mozilla.org/dom/json;1", "nsIJSON", "createInstance");