'List enabled service providers for Service Catalog.
Service Provider in a catalog contains three attributes: ``id``,
``auth_url``, ``sp_url``, where:
- id is a unique, user defined identifier for service provider object
- auth_url is an authentication URL of remote Keystone
- sp_url a URL accessible at the remote service provider where SAML
assertion is transmitted.
:returns: list of dictionaries with enabled service providers
:rtype: list of dicts'

@MEMOIZE
def get_enabled_service_providers(self):

    def normalize(sp):
        ref = {'auth_url': sp.auth_url, 'id': sp.id, 'sp_url': sp.sp_url}
        return ref
    service_providers = self.driver.get_enabled_service_providers()
    return [normalize(sp) for sp in service_providers]
