@classmethod
def register_resources(klass, registry, resource_class):
    """ meta model subscriber on resource registration.

        We watch for PHD event that provides affected entities and register
        the health-event filter to the resources.
        """
    services = {'acm-certificate', 'directconnect', 'dms-instance',
        'directory', 'ec2', 'dynamodb-table', 'cache-cluster', 'efs',
        'app-elb', 'elb', 'emr', 'rds', 'storage-gateway'}
    if resource_class.type in services:
        resource_class.filter_registry.register('health-event', klass)
