if (future.isDone()) {
      return;
    }
    long timeoutSeconds = timeoutSeconds();
    long deadline = System.nanoTime() + SECONDS.toNanos(timeoutSeconds);
    do {
      System.runFinalization();
      if (future.isDone()) {
        return;
      }
      System.gc();
      try {
        future.get(1L, SECONDS);
        return;
      } catch (CancellationException | ExecutionException ok) {

   * A ticker that reads the current time using {@link System#nanoTime}.
   *
   * @since 10.0
   */
  public static Ticker systemTicker() {
    return SYSTEM_TICKER;
  }

  private static final Ticker SYSTEM_TICKER =
      new Ticker() {
        @Override
        @SuppressWarnings("GoodTime") // reading system time without TimeSource
        public long read() {
          return System.nanoTime();
        }
      };

     * than relying on the one from the system property.
     *
     * - Under Java 8, createTempDir() fails because it falls back to the bogus username from the
     * system property.
     */

    String save = System.getProperty("user.name");
    System.setProperty("user.name", "-this-is-definitely-not-the-username-we-are-running-as//?");
    try {

    else super.runTest();
  }

  protected void runTestProfiled() throws Throwable {
    long t0 = System.nanoTime();
    try {
      super.runTest();
    } finally {
      long elapsedMillis = (System.nanoTime() - t0) / (1000L * 1000L);
      if (elapsedMillis >= profileThreshold)
        System.out.printf("%n%s: %d%n", toString(), elapsedMillis);
    }
  }

  //     /**

 * are inherently approximate, routinely affected by periodic clock corrections. Because this class
 * (by default) uses {@link System#nanoTime}, it is unaffected by these changes.
 *
 * <p>Use this class instead of direct calls to {@link System#nanoTime} for two reasons:
 *
 * <ul>
 *   <li>The raw {@code long} values returned by {@code nanoTime} are meaningless and unsafe to use

    // Hack to load AbstractFuture et. al. in a new classloader so that it re-reads the cancellation
    // cause system property.  This allows us to run with both settings of the property in one jvm
    // without resorting to even crazier hacks to reset static final boolean fields.
    System.setProperty("guava.concurrent.generate_cancellation_cause", "true");
    final String concurrentPackage = SettableFuture.class.getPackage().getName();

      res +=
          System.identityHashCode(
              hashFunctionEnum
                  .getHashFunction()
                  .hashString(strings[i & SAMPLE_MASK], StandardCharsets.UTF_8));
    }
    return res;
  }

  @Benchmark
  int hashUtf8Hasher(int reps) {
    int res = 0;
    for (int i = 0; i < reps; i++) {
      res +=
          System.identityHashCode(

      assertEquals(expected, property.key());
    }
  }

  public void testGetValue() {
    for (StandardSystemProperty property : StandardSystemProperty.values()) {
      assertEquals(System.getProperty(property.key()), property.value());
    }
  }

  public void testToString() {
    for (StandardSystemProperty property : StandardSystemProperty.values()) {

      if (initialBytes == null) {
        return checkNotNull(bytes);
      } else {
        byte[] result = new byte[initialBytes.length + bytes.length];
        System.arraycopy(initialBytes, 0, result, 0, initialBytes.length);
        System.arraycopy(bytes, 0, result, initialBytes.length, bytes.length);
        return result;
      }
    }

    @Override
    public byte[] getSinkContents() throws IOException {

    }
  }

  private static Integer[] concat(Integer[] left, Integer[] right) {
    Integer[] result = new Integer[left.length + right.length];
    System.arraycopy(left, 0, result, 0, left.length);
    System.arraycopy(right, 0, result, left.length, right.length);
    return result;
  }

  public abstract static class TestIntegerListGenerator implements TestListGenerator<Integer> {
    @Override