WeekendSqls 的工具类，提供一系列静态方法，减少泛型参数的指定，使代码更简洁、清晰
直接使用WeekSqls，以下的查询需要指定两次Country类：
List
selectByWeekendSql = mapper.selectByExample(new Example.Builder(Country.class)
.where(WeekendSqls.custom().andLike(Country::getCountryname, "%a%")
.andGreaterThan(Country::getCountrycode, "123"))
.build());
使用 WeekendSqlsUtils，只需指定一次Country类：
List selectByWeekendSql = mapper.selectByExample(new Example.Builder(Country.class)
.where(WeekendSqlsUtils.andLike(Country::getCountryname, "%a%")
.andGreaterThan(Country::getCountrycode, "123"))
.build());
建议使用 import static，代码会简洁一些
import static tk.mybatis.mapper.weekend.WeekendSqlsUtils.andLike;
List selectByWeekendSql = mapper.selectByExample(new Example.Builder(Country.class)
.where(andLike(Country::getCountryname, "%a%")
.andGreaterThan(Country::getCountrycode, "123"))
.build());