def init(cls, typ, class2type):
        """
        Defines custom fields in the value factory so that the importer can find them
        @param typ
        @param class2type
        """
        field = typ.getField(cls.FIELD_NAME)
        class2type.put( StrStrHashMap , typ )
        typ.setComponentType( StrStrHashMap )
        typ.setImportExportHelper( StrStrHashMapSerializer(typ, field))
        typ.putValidator(field, Validator_object.get(1))
        typ.lock()
def create_snapshot(self, volume_id, **kwargs):
        """
        Creates a new snapshot.
        volume_id(Required): id of the volume.
        force: Create a snapshot even if the volume attached (Default=False)
        display_name: Optional snapshot Name.
        display_description: User friendly snapshot description.
        """
        post_body = {'volume_id': volume_id}
        post_body.update(kwargs)
        post_body = json.dumps({'snapshot': post_body})
        resp, body = self.post('snapshots', post_body)
        body = json.loads(body)
        return resp, body['snapshot']