When we run our test cases in parallel using TestNg in selenium, you might have faced issues like some environmental, or some unknown issues halting the parallel execution.
Parallel execution is nothing but running the selenium in multiple threads, when one thread interrupts the other thread then JVM throws exceptions
Like webdriver listener we have to wrap the webdriver instance using the ThreadGuard class, for that purpose we a method called
WebDriver driver = ThreadGuard.protect(new FirefoxDriver());
This class has no importance than protecting the webdriver on the multi-threads.