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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_driver(driver_type):
 """Get webdriver."""

    if driver_type == 'phantomjs':
        return webdriver.PhantomJS(service_log_path=os.path.devnull)
    if driver_type == 'firefox':
        return webdriver.Firefox(firefox_options=FIREFOXOPTIONS)
    elif driver_type == 'chrome':
        chrome_options = webdriver.ChromeOptions()
        for arg in CHROME_WEBDRIVER_ARGS:
            chrome_options.add_argument(arg)
        return webdriver.Chrome(chrome_options=chrome_options)
    else:
        raise USPSError('{} not supported'.format(driver_type))