**Remove pre-condition**: In MongoDB, if a document contains duplicate keys, only the last occurrence of the key will take precedence.
{"id":"10", "id":"100"}In this case, the final value of "id" will be "100".
Source: NoSQL Injection/README.md in PayloadsAllTheThings. From PayloadsAllTheThings by Swissky and contributors. MIT License, Copyright (c) 2019 Swissky.