code: public static WebClient getHtmlUnitDriverWebClient(final WebDriver webDriver) {
  		WebDriver driver = webDriver;
  		driver = getWrappedDriver(driver);
  		checkArgument(driver instanceof JFunkHtmlUnitWebDriver, "Specified WebDriver is no JFunkHtmlUnitDriver: " + driver);
  		return ((JFunkHtmlUnitWebDriver) driver).getWebClient();
  	}
docs: Gets the {@link WebClient} of the specified {@link WebDriver}. Calls
  {@link #getWrappedDriver(WebDriver)} on the given {@link WebDriver} and checks that it is a
  {@link JFunkHtmlUnitWebDriver}.
  
  @param webDriver
  the web driver
  @return the {@link WebClient}
  @throws IllegalArgumentException
  if the specified {@link WebDriver} is no {@link JFunkHtmlUnitWebDriver}