public WebSocketServiceBuilder allowedOrigin(Pattern regex) {
        return allowedOrigin(requireNonNull(regex, "regex").asPredicate());
    }
Sets the regex pattern to evaluate whether an origin is allowed. The same-origin is allowed by default.

@see <a href="https://datatracker.ietf.org/doc/html/rfc6455#section-10.2">Origin Considerations</a>
core/src/main/java/com/linecorp/armeria/server/websocket/WebSocketServiceBuilder.java