How to set detail on an eventpattern in java

[cyberworkz]

Could someone help on how you can set the filter pattern in the EventPattern class in Java? I have the following pattern:

{
  "source": ["aws.s3"],
  "detail-type": ["Object Deleted"],
  "detail": {
    "object": {
      "key": [{
        "prefix": "original"
      }, {
        "prefix": "completed"
      }]
    }
  }
}

How does this map to the detail property of EventPattern which is a Map<String, Object>? I have the following in my stack, but it does not work in cdk version 1.160

 Rule.Builder.create(this, "s3ToSQSEventRule")
                .eventPattern(EventPattern.builder()
                        .source(List.of("aws.s3"))
                        .resources(List.of(valtimoBucket.getBucketArn()))
                        .detailType(List.of("Object Deleted"))
                        .detail(Map.of("object", " \"key\": [{" +
                               "        \"prefix\": \"original\"" +
                               "      }, {" +
                               "        \"prefix\": \"completed\"" +
                                "      }]"))
                        .region(List.of("eu-central-1"))
                        .build())
                .targets(List.of(SqsQueue.Builder.create(s3DeletionQueue).build()))
                .build();

The S3 event message looks like the following:

{
  "version": "0",
  "id": "762f8501-3ca9-fdbe-528a-d3b07801fea2",
  "detail-type": "Object Deleted",
  "source": "aws.s3",
  "account": "523803447397",
  "time": "2022-06-27T11:27:04Z",
  "region": "eu-central-1",
  "resources": [
    "arn:aws:s3:::bbf-test"
  ],
  "detail": {
    "version": "0",
    "bucket": {
      "name": "bbf-test"
    },
    "object": {
      "key": "original/1122526c-ebe3-4c43-a8a1-daf26ec8c114/20220614125052239348265_example-document.pdf",
      "etag": "d41d8cd98f00b204e9800998ecf8427e",
      "sequencer": "0062B99408CC87DCEF"
    },
    "request-id": "X9HTB3VWX7J8E22D",
    "requester": "523803447397",
    "source-ip-address": "213.127.182.74",
    "reason": "DeleteObject",
    "deletion-type": "Delete Marker Created"
  }
}

Currently, I get the following error when deploying this stack:

Event pattern is not valid. Reason: "object" must be an object or an array
 at [Source: (String)"{"detail-type":["Object Deleted"],"resources":["arn:aws:s3:::bbf-test"],"detail":{"object":" \"key\": [{        \"prefix\": \"original\"      }, {        \"prefix\": \"completed\"      }]"},"source":["aws.s3"],"region":["eu-central-1"]}"; line: 1, column: 101] (Service: AmazonCloudWatchEvents; Status Code: 400; Error Code: InvalidEventPatternException; Request ID: a5628aec-b2fb-4ef8-9665-dca2e5ab280d; Proxy: null)