Selenium script to enable add-on on firefox browser.!

File file = new File("C:\\Users\\NHCE\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles\\eayvhft0.default\\extensions\\firebug@software.joehewitt.com.xpi");
FirefoxProfile profile = new FirefoxProfile();
profile.addExtension(file);
profile.setPreference("extensions.firebug.currentVersion", "2.0.9");

WebDriver driver = new FirefoxDriver(profile);