### Question:
SauceSession { public RemoteWebDriver start() { driver = createRemoteWebDriver(getSauceUrl(), sauceOptions.toCapabilities()); return driver; } SauceSession();  SauceSession(SauceOptions options); RemoteWebDriver start(); URL getSauceUrl(); void stop(Boolean passed); void stop(String result);  }### Answer:
@Test(expected = SauceEnvironmentVariablesNotSetException.class) public void startThrowsErrorWithoutUsername() { doReturn(null).when(sauceOptions).getEnvironmentVariable("SAUCE_USERNAME"); sauceOptsSession.start(); }
@Test(expected = SauceEnvironmentVariablesNotSetException.class) public void startThrowsErrorWithoutAccessKey() { doReturn(null).when(sauceOptions).getEnvironmentVariable("SAUCE_ACCESS_KEY"); sauceOptsSession.start(); }