Optional<BinaryNode> root = Optional.absent();
        for (int i = 0; i < size; i++) {
          root = Optional.of(new BinaryNode(rng.nextInt(), root, Optional.<BinaryNode>absent()));
        }
        return root;
      }
    },
    ALL_RIGHT {
      @Override
      Optional<BinaryNode> createTree(int size, Random rng) {
        Optional<BinaryNode> root = Optional.absent();

      @Override
      long treeAggregate(@CheckForNull AvlNode<?> root) {
        return (root == null) ? 0 : root.totalCount;
      }
    },
    DISTINCT {
      @Override
      int nodeAggregate(AvlNode<?> node) {
        return 1;
      }

      @Override
      long treeAggregate(@CheckForNull AvlNode<?> root) {
        return (root == null) ? 0 : root.distinctElements;
      }
    };

    name: "${{ matrix.root-pom }} on JDK ${{ matrix.java }} on ${{ matrix.os }}"
    strategy:
      matrix:
        os: [ ubuntu-latest ]
        java: [ 8, 11, 17, 21 ]
        root-pom: [ 'pom.xml', 'android/pom.xml' ]
        include:
          - os: windows-latest
            java: 21
            root-pom: pom.xml
    runs-on: ${{ matrix.os }}
    env:
      ROOT_POM: ${{ matrix.root-pom }}
    steps:

   */
  private static final SuccessorsFunction<Character> TWO_TREES = createDirectedGraph("ab", "cd");

  /**
   * A graph consisting of a single root {@code a}:
   *
   * <pre>{@code
   * a
   * }</pre>
   */
  private static final SuccessorsFunction<Character> SINGLE_ROOT = createSingleRootGraph();

  /**
   * A graph that is not a tree (for example, it has two antiparallel edge between {@code e} and

    assertGoodFeatureEnum(CollectionSize.class);
    assertGoodFeatureEnum(MapFeature.class);
  }

  private static String rootLocaleFormat(String format, Object... args) {
    return String.format(Locale.ROOT, format, args);
  }

      spec.refreshDuration = duration;
      spec.refreshTimeUnit = unit;
    }
  }

  private static String format(String format, Object... args) {
    return String.format(Locale.ROOT, format, args);
  }

   *     arbitrary past or present time
   */
  abstract long reserveEarliestAvailable(int permits, long nowMicros);

  @Override
  public String toString() {
    return String.format(Locale.ROOT, "RateLimiter[stableRate=%3.1fqps]", getRate());
  }

  abstract static class SleepingStopwatch {
    /** Constructor for use by subclasses. */
    protected SleepingStopwatch() {}

    /*

      sleepMicros("U", MILLISECONDS.toMicros(millis));
    }

    void sleepMicros(String caption, long micros) {
      instant += MICROSECONDS.toNanos(micros);
      events.add(caption + String.format(Locale.ROOT, "%3.2f", (micros / 1000000.0)));
    }

    @Override
    protected void sleepMicrosUninterruptibly(long micros) {
      sleepMicros("R", micros);
    }

    String readEventsAndClear() {
      try {

 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>to be replaced with the more compact
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   checkArgument(value >= 0, "input is negative: %s", value);
 *   // calculate square root
 * }
 * }</pre>
 *
 * <p>so that a hypothetical bad caller of this method, such as:
 *

    assertThat(expected.getMessage()).contains("inner class");
  }

  private static String rootLocaleFormat(String format, Object... args) {
    return String.format(Locale.ROOT, format, args);
  }

  static class OverridesEquals {
    @SuppressWarnings("EqualsHashCode")
    @Override
    public boolean equals(@Nullable Object o) {
      return true;
    }
  }