This rule flags references to the jakarta.websocket.EndpointConfig.getUserProperties(),
jakarta.websocket.server.ServerEndpointConfig.getUserProperties(), and
jakarta.websocket.ClientEndpointConfig.getUserProperties() methods. The map returned by the
getUserProperties() method is now a copy per endpoint instance (per websocket session). As a result,
the user property data is no longer shared between sessions. Check whether your usage of the method needs to be
updated to handle the new behavior.
For more Jakarta 10 migration information, see Differences between Jakarta WebSocket 2.1 and 2.0.
Also, see the WebSocket 2.1 Javadoc.