- If the `XRPFees` feature is enabled, the `fee_ref` field will be
removed from the [ledger subscription stream](https://xrpl.org/subscribe.html#ledger-stream), because it will no longer
have any meaning.
Unit tests for API changes
The following information is useful to developers contributing to this project:
The purpose of unit tests is to catch bugs and prevent regressions. In general, it often makes sense to create a test function when there is a breaking change to the API. For APIs that have changed in a new API version, the tests should be modified so that both the prior version and the new version are properly tested.
To take one example: for `account_info` version 1, WebSocket and JSON-RPC behavior should be tested. The latest API version, i.e. API version 2, should be tested over WebSocket, JSON-RPC, and command line.