def __init__(self, url, user_data_dir=None):
    self.client = None
    for cls in [Chrome, Chromium, Firefox]:
        if cls.available():
            self.client = cls(url, user_data_dir)
            break
    if (self.client is None):
        raise Exception('No suitable client found!')
def __init__(self, url, user_data_dir=None):
    self.client = None
    for cls in [Chrome, Chromium, Firefox]:
        if cls.available():
            self.client = cls(url, user_data_dir)
            break
    if (self.client is None):
        raise Exception('No suitable client found!')