public static Function<? super HttpClient, BraveClient> newDecorator(
            HttpTracing httpTracing) {
        try {
            ensureScopeUsesRequestContext(httpTracing.tracing());
        } catch (IllegalStateException e) {
            logger.warn("{} - it is appropriate to ignore this warning if this client is not being used " +
                        "inside an Armeria server (e.g., this is a normal spring-mvc tomcat server).",
                        e.getMessage());
        }
        return delegate -> new BraveClient(delegate, httpTracing);
    }
Creates a new tracing {@link HttpClient} decorator using the specified {@link HttpTracing} instance.
brave/brave6/src/main/java/com/linecorp/armeria/client/brave/BraveClient.java