private WebSocketClientBuilder webSocketClientBuilder() {
        final boolean hasHttps = hasHttps();
        final String hostAndPort = hasHttps ? "wss://" + httpsUri().getAuthority()
                                            : "ws://" + httpUri().getAuthority();
        final WebSocketClientBuilder webSocketClientBuilder = WebSocketClient.builder(hostAndPort);
        if (hasHttps) {
            webSocketClientBuilder.factory(ClientFactory.insecure());
        }

        try {
            configureWebSocketClient(webSocketClientBuilder);
        } catch (Exception e) {
            throw new IllegalStateException("failed to configure a WebSocketClient", e);
        }
        return webSocketClientBuilder;
    }
Returns the {@link WebSocketClient} configured
by {@link #configureWebSocketClient(WebSocketClientBuilder)}.
junit5/src/main/java/com/linecorp/armeria/internal/testing/ServerRuleDelegate.java