'Returns Ext Resources.'

@classmethod
def get_resources(cls):

    exts = []
    plugin = directory.get_plugin()
    for resource_name in ['security_group', 'security_group_rule']:
        collection_name = (resource_name.replace('_', '-') + 's')
        params = RESOURCE_ATTRIBUTE_MAP.get((resource_name + 's'), dict())
        resource_registry.register_resource_by_name(resource_name)
        controller = base.create_resource(collection_name, resource_name, plugin, params, allow_bulk=True, allow_pagination=True, allow_sorting=True)
        ex = extensions.ResourceExtension(collection_name, controller, attr_map=params)
        exts.append(ex)
    return exts
