private FieldSpec f_orderBy() {
        return FieldSpec.builder(fluent.updateOrderBy(),
                "orderBy", Modifier.PUBLIC, Modifier.FINAL)
            .initializer("new $T(this)", fluent.updateOrderBy())
            .build();
    }
public final UpdateOrderBy orderBy = new UpdateOrderBy(this);

@return FieldSpec
fluent-mybatis-processor/src/main/java/cn/org/atool/fluent/processor/mybatis/filer/segment/UpdaterFiler.java