[BUG] aws-node-mongodb-atlas idempotent issue

[ao7777]

AWS lambda requires that users should write idempotent functions.
However, some functions in aws-node-mongodb-atlas do not ensure idempotence. For example, performQuery() may insert more than one pet into the DynamoDB table when the function fails and is retried by the lambda platform.

I was wondering whether it is a bug or the function does not need to be idempotent.

Please let me know if I've missed something or if my understanding of the code is incorrect. Thanks!