code: package io.ray.test;
  
  import io.ray.api.ActorHandle;
  import io.ray.api.ObjectRef;
  import io.ray.api.Ray;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.testng.annotations.Test;
  
  public class LoggingPerfTest extends BaseTest {
  
    private static final Logger LOG = LoggerFactory.getLogger(LoggingPerfTest.class);
  
    private static class LoggingPerfActor {
  
      public Long measure() {
        final int count = 2000000;
        final long startMs = System.currentTimeMillis();
        for (int i = 0; i < count; ++i) {
          LOG.info("hello world");
        }
        final long endMs = System.currentTimeMillis();
        return endMs - startMs;
      }
    }
  
    @Test
    public void testLoggingPerf() {
      ActorHandle<LoggingPerfActor> actor = Ray.actor(LoggingPerfActor::new).remote();
      ObjectRef<Long> took = actor.task(LoggingPerfActor::measure).remote();
      LOG.info("It took {} milliseconds.", took.get());
    }
  }
  