def METHOD_NAME(self):
    from ckanext.hdx_users.helpers.permissions import Permissions
    showcase_dict = generate_test_showcase(SYSADMIN, 'dataviz_showcase', True)
    showcase_dict['notes'] = 'Modified'
    showcase_dict['image_url'] = None
    user_with_permission = factories.User(name='user_with_permission', email='another_user@hdx.hdxtest.org')
    Permissions(user_with_permission['id']).set_permissions(
        {'user': SYSADMIN},
        [Permissions.PERMISSION_MANAGE_CAROUSEL]
    )
    context = {'model': model, 'session': model.Session, 'user': 'user_with_permission'}
    showcase_dict = _get_action('ckanext_showcase_update')(context, showcase_dict)
    assert showcase_dict['in_dataviz_gallery'] is True, \
        'A user with carousel permission should be allowed to update a dataviz showcase'
    del showcase_dict['dataviz_label']
    try:
        _get_action('ckanext_showcase_update')(context, showcase_dict)
        assert False
    except ValidationError as e:
        assert True, 'Validation should fail for dataviz showcases without "dataviz_label"'