code: public Javalin wsBefore(@NotNull String path, @NotNull Consumer<WsHandler> wsHandler) {
          return staticInstance().wsBefore(prefixPath(path), wsHandler);
      }
docs: Adds a WebSocket before handler for the specified path to the {@link Javalin} instance.
  The method can only be called inside a {@link Javalin#routes(EndpointGroup)}.