'Initialize the page.
Arguments:
browser (Browser): The browser instance.
course_id (unicode): The course in which the user is enrolling.
Keyword Arguments:
entry_point (str): Where to begin the flow; must be one of \'start-flow\',
\'upgrade\', \'verify-now\', verify-later\', or \'payment-confirmation\'.
Raises:
ValueError'

def __init__(self, browser, course_id, entry_point='start-flow'):

    super(PaymentAndVerificationFlow, self).__init__(browser)
    self._course_id = course_id
    if (entry_point not in ['start-flow', 'upgrade', 'verify-now', 'verify-later', 'payment-confirmation']):
        raise ValueError("Entry    point    must    be    either    'start-flow',    'upgrade',    'verify-now',    'verify-later',    or    'payment-confirmation'.")
    self._entry_point = entry_point
