// This lock protects the task so we can ensure that none of the template methods (startUp,
    // shutDown or runOneIteration) run concurrently with one another.
    // TODO(lukes): why don't we use ListenableFuture to sequence things? Then we could drop the
    // lock.
    private final ReentrantLock lock = new ReentrantLock();

    @WeakOuter
    final class Task implements Runnable {

 * A container class for the five sample elements we need for testing.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public class SampleElements<E extends @Nullable Object> implements Iterable<E> {
  // TODO: rename e3, e4 => missing1, missing2
  private final E e0;
  private final E e1;
  private final E e2;
  private final E e3;
  private final E e4;

  public SampleElements(E e0, E e1, E e2, E e3, E e4) {

  //
  // Future versions of the JMM may revise safe construction semantics in such a way that we can
  // safely publish these objects and we won't need this whole discussion.
  // TODO(user,lukes): consider adding volatile to all these fields since in current known JVMs
  // that should resolve the issue. This comes at the cost of adding more write barriers to the
  // implementations.

        .addEqualityGroup(Range.all(), Range.all())
        .addEqualityGroup("Phil")
        .testEquals();
  }

  @GwtIncompatible // TODO(b/148207871): Restore once Eclipse compiler no longer flakes for this.
  @J2ktIncompatible // TODO(b/148207871): Likewise, or once J2KT uses javac instead of Eclipse.
  public void testLegacyComparable() {

  ): List<Header> {
    continuation.left = length
    continuation.length = continuation.left
    continuation.padding = padding
    continuation.flags = flags
    continuation.streamId = streamId

    // TODO: Concat multi-value headers with 0x0, except COOKIE, which uses 0x3B, 0x20.
    // http://tools.ietf.org/html/draft-ietf-httpbis-http2-17#section-8.1.2.5
    hpackReader.readHeaders()
    return hpackReader.getAndResetHeaderList()

              <arg>-XDcompilePolicy=simple</arg>
              <arg>--should-stop=ifError=FLOW</arg>

              <!-- https://errorprone.info/docs/installation#maven -->
              <!-- TODO(cpovirk): Enable NullArgumentForNonNullParameter for
                   prod code. It's disabled automatically for "test code"
                   (which is good: our tests have intentional violations), but

  public void testSetCountConditional_oldCountTooSmallNonzero() {
    initThreeCopies();
    assertFalse(
        "setCount() with a too-small oldCount should return false",
        getMultiset().setCount(e0(), 1, 5));
    expectContents(nCopies(3, e0()));
  }

  /*
   * TODO: test that unmodifiable multisets either throw UOE or return false
   * when both are valid options. Currently we test the UOE cases and the

/**
 * Unit tests for {@link Callables}.
 *
 * @author Isaac Shum
 */
@GwtCompatible
@NullUnmarked
public class CallablesTest extends TestCase {

  @J2ktIncompatible // TODO(b/324550390): Enable
  public void testReturning() throws Exception {
    assertNull(Callables.returning(null).call());

    Object value = new Object();
    Callable<Object> callable = Callables.returning(value);

  }

  @Override
  public NavigableSet<E> elementSet() {
    return (NavigableSet<E>) super.elementSet();
  }

  @LazyInit private transient @Nullable UnmodifiableSortedMultiset<E> descendingMultiset;

  // TODO(b/418181860): This method creates retain cycles in J2ObjC. In order to break the cycle,
  // there needs to be separate classes for primary and descending multiset, where the primary one

## TODO

- Richer progress UI is not present at the moment, this will be addressed in subsequent releases. Currently however a RATE of data transfer and usage increase is displayed via `mc`.