Optional
Only set if returnItemCollectionMetrics set appropriately on request and item(s) contained any collections Batch results will contain one item per DynamoDB request. In the case of single page operations this will be an array of length 1
https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_ItemCollectionMetrics.html
Only set if returnItemCollectionMetrics set appropriately on request and item(s) contained any collections Batch results will contain one item per DynamoDB request. In the case of single page operations this will be an array of length 1