'Verify that we get an error message when omitting a username.'

def test_no_username_given(self):

    cohort = CohortFactory(course_id=self.course.id, users=[])
    response_dict = self.request_remove_user_from_cohort(None, cohort)
    self.verify_removed_user_from_cohort(None, response_dict, cohort, expected_error_msg='No    username    specified')
