'Initialize the page.
Arguments:
browser (Browser): The browser instance.
Keyword Args:
start_page (str): Whether to start on the login or register page.
course_id (unicode): If provided, load the page as if the user
is trying to enroll in a course.'

def __init__(self, browser, start_page='register', course_id=None):

    super(CombinedLoginAndRegisterPage, self).__init__(browser)
    self._course_id = course_id
    if (start_page not in ['register', 'login']):
        raise ValueError("Start    page    must    be    either    'register'    or    'login'")
    self._start_page = start_page
