TooTallNate/Java-WebSocket — comment on commit eee48d144d358c4f8b0878a7a5421fab857946b3
File: src/net/tootallnate/websocket/WebSocketServer.java line 178
By Davidiusdadi:

Yes its a breaking change that would break any code which depends on this function. The motivation was:

1. Wrapping a set is faster than an array copy(and allocation).
2. The wrapped set will always reflect the current connections and not a recent snapshot.

The overall websocket implementation makes it easy to react to messages. But it kind of inconvenient to manage your connections.
And for those who want to (like i do) this change offers the capability to do that with fairly low overhead.