问COS批量删除报错，'code': 'MalformedXML'？

config = CosConfig(Region=region, SecretId=secretId, SecretKey=secretKey,
                   Scheme="http")

client = CosS3Client(config)
res = objects = {
    "Object": [
        {'key': '1595847998160_微信图片_20200611153701.png'},
        {'key': '1595847998157_619hdhsy.jpg'},
        {'key': '1595847998149_619hd.jpg'}
    ]
}
respense = client.delete_objects(
    Bucket=bucket,
    Delete=objects
)