MyBatis & MyBatis Generator version dependency issue regarding java.util.Optional support

[Huijie Shi (Forgotten River)]

java.util.Optional is introduced in MyBatis 3.5.0 and MyBatis Generator introduced it for MyBatis3DynamicSQL in 1.4.0, which means for MyBatis3DynamicSQL, all code generated with MyBatis 1.4.0+ is only compatible with MyBatis 3.5.0+, which makes the information on the introduction page (https://mybatis.org/generator/) wrong.