@Override
    public ShardingSphereSchema swapToObject(final YamlShardingSphereSchema yamlConfig) {
        return Optional.ofNullable(yamlConfig).map(this::swapSchema).orElseGet(() -> new ShardingSphereSchema(yamlConfig.getName()));
    }
@Test
    void assertSwapToShardingSphereSchemaWithoutTable() {
        YamlShardingSphereSchema yamlSchema = YamlEngine.unmarshal(readYAML(YAML_WITHOUT_TABLE), YamlShardingSphereSchema.class);
        assertTrue(new YamlSchemaSwapper().swapToObject(yamlSchema).getAllTableNames().isEmpty());
    }