'Scenario: On the Certificates tab of the Instructor Dashboard,
Error message appears if student being added already exists in certificate exceptions list
Given that I am on the Certificates tab on the Instructor Dashboard
When I fill in student username that already is in the list and click \'Add Exception\' button
Then Error Message should say \'User (username/email={user}) already in exception list.\''

def test_error_on_duplicate_certificate_exception(self):

    self.certificates_section.add_certificate_exception(self.user_name, '')
    self.certificates_section.add_certificate_exception(self.user_name, '')
    self.assertIn('{user}    already    in    exception    list.'.format(user=self.user_name), self.certificates_section.message.text)
