DurationFormat (Spring Boot API)

```
@Target(FIELD)
@Retention(RUNTIME)
@Documented
public @interface DurationFormat
```
Annotation that can be used to indicate the format to use when converting a Duration.
从以下版本开始:
2.0.0

- 必需元素概要
  所需元素
  修饰符和类型必需的元素说明
  DurationStyle value
  The duration format style.

- 元素详细资料
  - value
```
DurationStyle value
```
    The duration format style.
    返回:
    the duration format style.