flink 算子中定义的对象内存 checkpoint时会保存到 state中吗

例如，自定义Aggregate函数，accumulator的 Set 中的内容会保存到state中么 代码如下：

public class AggregateResult implements Serializable {
    private String key;
    private Double result = 0.0;
    private Set<String> distinct;
}

public class DistinctCountFunction implements AggregateFunction<CalDetail, AggregateResult, AggregateResult> {

    @Override public AggregateResult createAccumulator() {
        AggregateResult result = new AggregateResult();
        result.setDistinct(new HashSet<>());
        return result;
    }

    @Override public AggregateResult add(CalDetail value, AggregateResult accumulator) {
        accumulator.setKey(value.getGroupKey());
        accumulator.getDistinct().add(value.getData());
        accumulator.setResult((double) accumulator.getDistinct().size());
        return accumulator;
    }

    @Override public AggregateResult getResult(AggregateResult accumulator) {
        return accumulator;
    }

    @Override public AggregateResult merge(AggregateResult a, AggregateResult b) {
    // 暂不处理
        return a;
    }
}