private CompletableFuture<String> makeCompletableFuture(final int sleepMillis, final AtomicBoolean timeout) {
        return CompletableFuture.supplyAsync(() -> {
            if (timeout.get()) {
                logger.debug("Timeout");
                return "Timeout";
            }
            try {
                Thread.sleep(100);
            } catch (InterruptedException ignore) {
            }
            logger.debug("RUN {}", sleepMillis);
            return "Completed";
        }, executor);
    }
Checks histograms for user node.
<pre>
    userNode ---> wasNode (2 agents)
</pre>
web/src/test/java/com/navercorp/pinpoint/web/applicationmap/appender/histogram/NodeHistogramAppenderTest.java