private fun startNextTask(): SerialTask? {
    taskRunner.assertLockHeld()

    val index = serialTaskQueue.indexOfFirst { it.isReady() }
    if (index == -1) return null

    val nextTask = serialTaskQueue.removeAt(index)
    currentTask = nextTask
    contextSwitchCount++
    nextTask.start()
    return nextTask
  }

  private interface SerialTask {
    /** Returns true if this task is ready to start. */

      } else {
        readyQueues.remove(taskQueue)
      }
    }

    if (coordinatorWaiting) {
      backend.coordinatorNotify(this@TaskRunner)
    } else {
      startAnotherThread()
    }
  }

  private fun beforeRun(task: Task) {
    assertLockHeld()

    task.nextExecuteNanoTime = -1L
    val queue = task.queue!!
    queue.futureTasks.remove(task)
    readyQueues.remove(queue)

 *     the same lambda function as passed into {@link #using(Function)}.
 *     <p>This class is scheduled to be removed in October 2019.
 */
// TODO(b/68134636): Remove by 2019-10
@Deprecated
@Beta
@GwtCompatible
public abstract class TreeTraverser<T> {
  /** Constructor for use by subclasses. */
  public TreeTraverser() {}

  /**

        this.handle = handle;
        final MsrpcSamrOpenDomain rpc = new MsrpcSamrOpenDomain(policyHandle, access, sid, this);
        handle.sendrecv(rpc);
        if (rpc.retval != 0) {
            throw new SmbException(rpc.retval, false);
        }
    }

    /**
     * Closes this SAM domain handle.
     *
     * @throws IOException if an I/O error occurs during handle closure
     */

            float.class,
            int.class,
            long.class,
            short.class,
            void.class);

    assertThrows(UnsupportedOperationException.class, () -> primitives.remove(boolean.class));
  }

  public void testAllWrapperTypes() {
    Set<Class<?>> wrappers = Primitives.allWrapperTypes();
    assertThat(wrappers)
        .containsExactly(
            Boolean.class,

  @Override
  public @Nullable V putIfAbsent(K key, V value) {
    return delegate().putIfAbsent(key, value);
  }

  @CanIgnoreReturnValue
  @Override
  public boolean remove(@Nullable Object key, @Nullable Object value) {
    return delegate().remove(key, value);
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V replace(K key, V value) {
    return delegate().replace(key, value);
  }

   * implementation, because {@code map.get()} returns a view collection that changes in the course
   * of a call to {@code remove()}. Thus, the expectation doesn't hold that {@code map.remove(x)}
   * returns the same value which {@code map.get(x)} did immediately beforehand.
   */
  @Override
  public void testRemove() {
    Map<String, Collection<Integer>> map;
    try {

    @Override
    public void close() throws CIFSException {
        if (this.next != null) {
            doClose();
        }
    }

    @Override
    public void remove() {
        throw new UnsupportedOperationException("remove");
    }

            final MsrpcDfsRootEnum rpc = new MsrpcDfsRootEnum(loc.getServer());
            handle.sendrecv(rpc);
            if (rpc.retval != 0) {
                throw new SmbException(rpc.retval, true);
            }
            return rpc.getEntries();
        }
    }

        doc.put("title", "Test");
        documentList.add(doc);

        QueryResponseList qrList = new QueryResponseList(documentList, 0, 10, 0);

        // Test removeAll and retainAll with empty collection
        assertFalse(qrList.removeAll(new ArrayList<>()));
        assertEquals(1, qrList.size());

        assertTrue(qrList.retainAll(new ArrayList<>()));
        assertEquals(0, qrList.size());
    }