how to take screen shot by using Selenium2 Grid

Selenium2Example1Test.java

import java.io.File;
import java.io.IOException;
import java.net.URL;

import org.apache.commons.io.FileUtils;
import org.junit.Assert;
import org.junit.Test;
import org.openqa.selenium.OutputType;
import org.openqa.selenium.Platform;
import org.openqa.selenium.TakesScreenshot;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.remote.Augmenter;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.remote.RemoteWebDriver;

public class Selenium2Example1Test {

  @Test
  public void test() throws IOException {
    // http://stackoverflow.com/questions/7080305/selenium2-taking-screenshots-with-selenium-grid-2
    // Instantiate a webDriver implementation
    // WebDriver webdriver = new FirefoxDriver();
    DesiredCapabilities capabilities = new DesiredCapabilities();
    capabilities.setBrowserName("firefox");
    // capabilities.setVersion("7");
    capabilities.setPlatform(Platform.MAC);
    WebDriver webdriver = new RemoteWebDriver(new URL(
        "http://localhost:4444/wd/hub"), capabilities);
    webdriver = new Augmenter().augment(webdriver);
    webdriver.get("https://github.com");
    File srcFile = ((TakesScreenshot) webdriver)
        .getScreenshotAs(OutputType.FILE);
    FileUtils.copyFile(srcFile, new File("./test003.png"));
    Assert.assertEquals("GitHub · Social Coding", webdriver.getTitle());
    webdriver.quit();
  }
}