static void delay(long millis) throws InterruptedException {
    long startTime = System.nanoTime();
    long ns = millis * 1000 * 1000;
    for (; ; ) {
      if (millis > 0L) Thread.sleep(millis);
      else // too short to sleep
      Thread.yield();
      long d = ns - (System.nanoTime() - startTime);
      if (d > 0L) millis = d / (1000 * 1000);
      else break;
    }
  }

    LARGE(UNEXPECTED_HANG_DELAY_MILLIS * 2, (2 * UNEXPECTED_HANG_DELAY_MILLIS) + "ms"),
    MAX(Long.MAX_VALUE, "+oo");

    final long millis;
    final String label;

    Timeout(long millis, String label) {
      this.millis = millis;
      this.label = label;
    }

    @Override
    public String toString() {
      return label;
    }
  }

    /** The key of the configuration. e.g. false */
    String FRAMEWORK_DEBUG = "framework.debug";

    /** The key of the configuration. e.g. 0 */
    String TIME_ADJUST_TIME_MILLIS = "time.adjust.time.millis";

    /** The key of the configuration. e.g. true */
    String MAIL_SEND_MOCK = "mail.send.mock";

    /** The key of the configuration. e.g. localhost:25 */

         * This method blocks until the thread completes or the timeout expires.
         *
         * @param mills maximum time to wait in milliseconds
         */
        public void awaitTermination(final long mills) {
            try {
                join(mills);
            } catch (final InterruptedException e) {
                if (logger.isDebugEnabled()) {

 * {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see
 * {@link PairedStatsTest}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsAccumulatorTest extends TestCase {

  private PairedStatsAccumulator emptyAccumulator;
  private PairedStatsAccumulator emptyAccumulatorByAddAllEmptyPairedStats;

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsTest extends TestCase {

  public void testCount() {
    assertThat(EMPTY_PAIRED_STATS.count()).isEqualTo(0);
    assertThat(ONE_VALUE_PAIRED_STATS.count()).isEqualTo(1);

import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link PairedStats}. This tests instances created by {@link
 * PairedStatsAccumulator#snapshot}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsTest extends TestCase {

  public void testCount() {
    assertThat(EMPTY_PAIRED_STATS.count()).isEqualTo(0);
    assertThat(ONE_VALUE_PAIRED_STATS.count()).isEqualTo(1);

 * {@link PairedStatsAccumulator#snapshot} method which returns {@link PairedStats} instances, see
 * {@link PairedStatsTest}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class PairedStatsAccumulatorTest extends TestCase {

  private PairedStatsAccumulator emptyAccumulator;
  private PairedStatsAccumulator emptyAccumulatorByAddAllEmptyPairedStats;

import java.util.Random;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Quantiles}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class QuantilesTest extends TestCase {

  /*
   * Since Quantiles provides a fluent-style API, each test covers a chain of methods resulting in

import java.util.Random;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Quantiles}.
 *
 * @author Pete Gillin
 */
@NullUnmarked
public class QuantilesTest extends TestCase {

  /*
   * Since Quantiles provides a fluent-style API, each test covers a chain of methods resulting in