'Verify that `addd_users_to_cohorts` successfully validates the
file content, uploads the input file, and triggers the
background task.'

def verify_success_on_file_content(self, file_content, mock_store_upload, mock_cohort_task):

    mock_store_upload.return_value = (None, 'fake_file_name.csv')
    self.client.login(username=self.staff_user.username, password='test')
    response = self.call_add_users_to_cohorts(file_content)
    self.assertEqual(response.status_code, 204)
    self.assertTrue(mock_store_upload.called)
    self.assertTrue(mock_cohort_task.called)
