*
   * <p><b>Comparison to {@code java.util.Optional}:</b> this class leaves the specific choice of
   * hash code unspecified, unlike the Java 8+ equivalent.
   */
  @Override
  public abstract int hashCode();

  /**
   * Returns a string representation for this instance.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this class leaves the specific string

     * then it behaves as "ordinary relocation": the coordinate is preserved from relocated artifact.
     * Finally, if right hand <code>GAV</code> is absent (line looks like <code>GAV&gt;</code>), the left hand matching
     * <code>GAV</code> is banned fully (from resolving).
     * <br/>
     * Note: the <code>&gt;</code> means project level, while <code>&gt;&gt;</code> means global (whole session level,

    if (bubbledTo == vacated) {
      // Could not bubble toTrickle up min levels, try moving
      // it from min level to max level (or max to min level) and bubble up
      // there.
      return heap.tryCrossOverAndBubbleUp(index, vacated, toTrickle);
    } else {
      return (bubbledTo < index) ? new MoveDesc<E>(toTrickle, elementData(index)) : null;
    }
  }

    //     imagine a line separating the first block from the second, we can proceed by exchanging
    //     the smaller of these blocks with the far end of the other one. That leaves us with a
    //     smaller version of the same problem.
    //     Say we are rotating abcdefgh by 5. We start with abcde|fgh. The smaller block is [fgh]:

    if (bubbledTo == vacated) {
      // Could not bubble toTrickle up min levels, try moving
      // it from min level to max level (or max to min level) and bubble up
      // there.
      return heap.tryCrossOverAndBubbleUp(index, vacated, toTrickle);
    } else {
      return (bubbledTo < index) ? new MoveDesc<E>(toTrickle, elementData(index)) : null;
    }
  }

       *
       * - In deleteDirectoryContents, the path argument may have no parent. Fortunately, all the
       *   *other* paths we process will be descendants of that. That leaves only the original path
       *   argument for us to consider. And the only place we call pathNotFound is from
       *   throwDeleteFailed, and the other place that we call throwDeleteFailed inside

       *
       * - In deleteDirectoryContents, the path argument may have no parent. Fortunately, all the
       *   *other* paths we process will be descendants of that. That leaves only the original path
       *   argument for us to consider. And the only place we call pathNotFound is from
       *   throwDeleteFailed, and the other place that we call throwDeleteFailed inside

   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override
  @DoNotCall("Always throws UnsupportedOperationException")
  @CheckForNull
  public final V remove(@CheckForNull Object o) {
    throw new UnsupportedOperationException();
  }

  /**
   * Guaranteed to throw an exception and leave the map unmodified.

    Range<K> lastRange = ranges.get(ranges.size() - 1);
    return Range.create(firstRange.lowerBound, lastRange.upperBound);
  }

  /**
   * Guaranteed to throw an exception and leave the {@code RangeMap} unmodified.
   *
   * @throws UnsupportedOperationException always
   * @deprecated Unsupported operation.
   */
  @Deprecated
  @Override

    Builder(int expectedKeys) {
      if (expectedKeys > 0) {
        builderMap = Platform.preservesInsertionOrderOnPutsMapWithExpectedSize(expectedKeys);
      }
      // otherwise, leave it null to be constructed lazily
    }

    Map<K, ImmutableCollection.Builder<V>> ensureBuilderMapNonNull() {
      Map<K, ImmutableCollection.Builder<V>> result = builderMap;
      if (result == null) {