//                                                                              Finish
    //                                                                              ======
    @Override
    public void finish() {
        rollback();
    }

    // ===================================================================================

                artifact = artifact.setVersion(snapshotMetadata.getExpandedVersion(artifact));
            }
        }

        return artifact;
    }

    @Override
    public Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts) {
        return Collections.emptyList();
    }

        ) {
          t.printStackTrace(System.out)
          latch.countDown()
        }
      },
    )

    check(latch.await(30, TimeUnit.SECONDS)) { "Timed out waiting for test $number to finish." }
    val endNanos = System.nanoTime()
    val tookMs = TimeUnit.NANOSECONDS.toMillis(endNanos - startNanos.get())
    println("Took ${tookMs}ms")
  }

  private fun getTestCount(): Long {

        return Collections.emptyList();
    }

    @Override
    public Artifact transformArtifact(Artifact artifact) {
        return artifact;
    }

    @Override
    public Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts) {
        return snapshots.values();
    }

    boolean lockAcquired = tryLockUninterruptibly(lock, 500, MILLISECONDS);

    assertFalse(lockAcquired);
    assertAtLeastTimePassed(stopwatch, 500);
    assertNotInterrupted();

    // finish locking thread
    lockThread.interrupt();
  }

  public void testTryLockTimeoutNotExceeded() {
    Stopwatch stopwatch = Stopwatch.createStarted();
    Lock lock = new ReentrantLock();

		outputQueue = outputQueue[:0]
		return true
	}

	var rec sql.Record
OuterLoop:
	for {
		if s3Select.statement.LimitReached() {
			if !sendRecord() {
				break
			}
			if err = writer.Finish(s3Select.getProgress()); err != nil {
				// FIXME: log this error.
				err = nil
			}
			break
		}

		if rec, err = s3Select.recordReader.Read(rec); err != nil {
			if err != io.EOF {
				break

if [[ "$TFCI_DOCKER_PULL_ENABLE" == 1 ]]; then
  # Simple retry logic for docker-pull errors. Sleeps for 15s if a pull fails.
  # Pulling an already-pulled container image will finish instantly, so
  # repeating the command costs nothing.
  docker pull "$TFCI_DOCKER_IMAGE" || sleep 15
  docker pull "$TFCI_DOCKER_IMAGE" || sleep 15
  docker pull "$TFCI_DOCKER_IMAGE"
fi 

        return Collections.emptyList();
    }

    @Override
    public Artifact transformArtifact(Artifact artifact) {
        return artifact;
    }

    @Override
    public Collection<? extends Metadata> finish(Collection<? extends Artifact> artifacts) {
        for (Artifact artifact : artifacts) {
            Object key = VersionsMetadata.getKey(artifact);
            if (processedVersions.get(key) == null) {

   *
   * <p>If another call to {@link #get} or {@link #getUnchecked} is currently loading the value for
   * {@code key}, simply waits for that thread to finish and returns its loaded value. Note that
   * multiple threads can concurrently load values for distinct keys.
   *
   * <p>Caches loaded by a {@link CacheLoader} will call {@link CacheLoader#load} to load new values

	}
	// Wait for all parallel RLock()s to succeed.
	for i := 0; i < numReaders; i++ {
		<-clocked
	}
	for i := 0; i < numReaders; i++ {
		cunlock <- true
	}
	// Wait for the goroutines to finish.
	for i := 0; i < numReaders; i++ {
		<-cdone
	}
}

// Borrowed from rwmutex_test.go
func TestParallelReaders(t *testing.T) {
	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(-1))