allocateIds在Google Cloud Datastore java库中的什么位置？

import com.google.cloud.datastore.Datastore;
import com.google.cloud.datastore.DatastoreOptions;
import com.google.cloud.datastore.Key;
import com.google.cloud.datastore.KeyFactory;

public class AllocateIdsExample {
    public static void main(String[] args) {
        // 创建Datastore实例
        Datastore datastore = DatastoreOptions.getDefaultInstance().getService();

        // 创建KeyFactory用于生成实体键
        KeyFactory keyFactory = datastore.newKeyFactory().setKind("MyEntity");

        // 分配一批唯一ID
        Key[] keys = datastore.allocateId(keyFactory.newKey(), keyFactory.newKey(), keyFactory.newKey());

        // 打印生成的ID
        for (Key key : keys) {
            System.out.println("Allocated ID: " + key.getId());
        }
    }
}