private WebClientBuilder webClientBuilder() {
        final boolean hasHttps = hasHttps();
        final WebClientBuilder webClientBuilder = WebClient.builder(hasHttps ? httpsUri() : httpUri());
        if (hasHttps) {
            webClientBuilder.factory(ClientFactory.insecure());
        }
        try {
            configureWebClient(webClientBuilder);
        } catch (Exception e) {
            throw new IllegalStateException("failed to configure a WebClient", e);
        }
        return webClientBuilder;
    }
Returns the {@link WebSocketClient} configured
by {@link #configureWebSocketClient(WebSocketClientBuilder)}.
junit5/src/main/java/com/linecorp/armeria/internal/testing/ServerRuleDelegate.java