'Stuff things into filter_properties.
Can be overridden in a subclass to add more data.'

def populate_filter_properties(self, request_spec, filter_properties):

    vol = request_spec['volume_properties']
    filter_properties['size'] = vol['size']
    filter_properties['availability_zone'] = vol.get('availability_zone')
    filter_properties['user_id'] = vol.get('user_id')
    filter_properties['metadata'] = vol.get('metadata')
    filter_properties['qos_specs'] = vol.get('qos_specs')
