public WebSocketService build() {
        final boolean allowAnyOrigin;
        final Predicate<? super String> originPredicate;
        if (allowedOrigins != null) {
            allowAnyOrigin = allowedOrigins.contains(ANY_ORIGIN);
            originPredicate = allowedOrigins::contains;
        } else {
            allowAnyOrigin = false;
            originPredicate = this.originPredicate;
        }
        return new DefaultWebSocketService(handler, fallbackService, maxFramePayloadLength, allowMaskMismatch,
                                           subprotocols, allowAnyOrigin, originPredicate, aggregateContinuation,
                                           serviceOptions);
    }
Returns a newly-created {@link WebSocketService} with the properties set so far.
core/src/main/java/com/linecorp/armeria/server/websocket/WebSocketServiceBuilder.java