//tag::include[]
package org.hibernate.validator.referenceguide.chapter02.typeargument.optional;
//end::include[]
import java.util.Optional;
//tag::include[]
public class Car {
private Optional<@MinTowingCapacity(1000) Integer> towingCapacity = Optional.empty();
public void setTowingCapacity(Integer alias) {
towingCapacity = Optional.of( alias );
}
//...
}
//end::include[]