'Return the default provider for a given service type.'

def get_default_service_provider(self, context, service_type):

    filters = {'service_type': [service_type], 'default': [True]}
    providers = self.get_service_providers(context, filters=filters)
    if (not providers):
        raise pconf.DefaultServiceProviderNotFound(service_type=service_type)
    return providers[0]
