NoClassDefFoundError: com/google/common/base/Function in selenium web driver : <p>I want to run my first selenium web driver program but I got an Exception in thread "main" java.lang.NoClassDefFoundError: com/google/common/base/Function</p>

<pre><code>public class SimpleSelenium {
    WebDriver driver = null;
String url = "http://www.google.com";

public static void main(String args[]){
    SimpleSelenium ss = new SimpleSelenium();
    ss.openBrowser();
    ss.getPage();
    ss.quitPage();
}

private void openBrowser() {
    driver = new FirefoxDriver();

}

private void quitPage() {
    driver.quit();

}

private void getPage() {
    driver.get(url);


}
</code></pre>
