如何在Spring Data Mongodb中GroupBy而不聚合？

<dependencies>
    <!-- Spring Data MongoDB -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-mongodb</artifactId>
    </dependency>
    <!-- MongoDB驱动 -->
    <dependency>
        <groupId>org.mongodb</groupId>
        <artifactId>mongo-java-driver</artifactId>
    </dependency>
</dependencies>

import org.springframework.data.mongodb.repository.Aggregation;
import org.springframework.data.mongodb.repository.MongoRepository;

public interface MyRepository extends MongoRepository<MyEntity, String> {
    
    @Aggregation(pipeline = {
        "{$group: {_id: '$field', count: {$sum: 1}}}",
        "{$project: {_id: 0, field: '$_id', count: 1}}"
    })
    List<GroupResult> groupByField();
}

List<GroupResult> result = myRepository.groupByField();