// Exists to test that our framework doesn't run it:
    @SuppressWarnings("unused")
    @ExampleDerivedFeature.Require({
      ExampleDerivedFeature.DERIVED_FEATURE_1,
      ExampleDerivedFeature.DERIVED_FEATURE_2
    })
    public void testRequiringTwoExplicitDerivedFeatures() throws Exception {
      doNotActuallyRunThis();
    }

    // Exists to test that our framework doesn't run it:

    // Exists to test that our framework doesn't run it:
    @SuppressWarnings("unused")
    @ExampleDerivedFeature.Require({
      ExampleDerivedFeature.DERIVED_FEATURE_1,
      ExampleDerivedFeature.DERIVED_FEATURE_2
    })
    public void testRequiringTwoExplicitDerivedFeatures() throws Exception {
      doNotActuallyRunThis();
    }

    // Exists to test that our framework doesn't run it:

   * connectedRange}, if such a range exists.
   *
   * <p>For example, the intersection of {@code [1..5]} and {@code (3..7)} is {@code (3..5]}. The
   * resulting range may be empty; for example, {@code [1..5)} intersected with {@code [5..7)}
   * yields the empty range {@code [5..5)}.
   *
   * <p>The intersection exists if and only if the two ranges are {@linkplain #isConnected
   * connected}.
   *

   * @param target a primitive {@code char} value
   * @return the least index {@code i} for which {@code array[i] == target}, or {@code -1} if no
   *     such index exists.
   */
  public static int indexOf(char[] array, char target) {
    return indexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public

   * @param target a primitive {@code double} value
   * @return the least index {@code i} for which {@code array[i] == target}, or {@code -1} if no
   *     such index exists.
   */
  public static int indexOf(double[] array, double target) {
    return indexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public

   * @param array an array of {@code int} values, possibly empty
   * @param target a primitive {@code int} value
   * @return the least index {@code i} for which {@code array[i] == target}, or {@code -1} if no
   *     such index exists.
   */
  public static int indexOf(int[] array, int target) {
    return indexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public

    throw new InvalidObjectException("Use SerializedForm");
  }

  /**
   * Not supported. Use {@link #toImmutableSortedMultiset} instead. This method exists only to hide
   * {@link ImmutableMultiset#toImmutableMultiset} from consumers of {@code
   * ImmutableSortedMultiset}.
   *
   * @throws UnsupportedOperationException always

@ElementTypesAreNonnullByDefault
public abstract class TreeTraverser<T> {

  /**
   * Returns a tree traverser that uses the given function to navigate from a node to its children.
   * This is useful if the function instance already exists, or so that you can supply a lambda
   * expressions. If those circumstances don't apply, you probably don't need to use this; subclass
   * {@code TreeTraverser} and implement its {@link #children} method directly.
   *

      }
      return null;
    }
  }

  private static final class InCompletionOrderState<T extends @Nullable Object> {
    // A happens-before edge between the writes of these fields and their reads exists, because
    // in order to read these fields, the corresponding write to incompleteOutputCount must have
    // been read.
    private boolean wasCancelled = false;
    private boolean shouldInterrupt = true;

   * available, a new Cell is created. Otherwise, if the slot
   * exists, a CAS is tried.  Retries proceed by "double hashing",
   * using a secondary hash (Marsaglia XorShift) to try to find a
   * free slot.
   *
   * The table size is capped because, when there are more threads
   * than CPUs, supposing that each thread were bound to a CPU,
   * there would exist a perfect hash function mapping threads to