* </ul>
 *
 * <h3>Understanding complex orderings</h3>
 *
 * <p>Complex chained orderings like the following example can be challenging to understand.
 *
 * <pre>{@code
 * Ordering<Foo> ordering =
 *     Ordering.natural()
 *         .nullsFirst()
 *         .onResultOf(getBarFunction)
 *         .nullsLast();
 * }</pre>
 *
 * Note that each chaining method returns a new ordering instance which is backed by the previous

 * </ul>
 *
 * <h3>Understanding complex orderings</h3>
 *
 * <p>Complex chained orderings like the following example can be challenging to understand.
 *
 * <pre>{@code
 * Ordering<Foo> ordering =
 *     Ordering.natural()
 *         .nullsFirst()
 *         .onResultOf(getBarFunction)
 *         .nullsLast();
 * }</pre>
 *
 * Note that each chaining method returns a new ordering instance which is backed by the previous

      }
    }
    return dummy;
  }

  @Benchmark
  int ordering(int reps) {
    int dummy = 0;
    if (mutable) {
      for (int i = 0; i < reps; i++) {
        dummy += ORDERING.sortedCopy(input).get(0);
      }
    } else {
      for (int i = 0; i < reps; i++) {
        dummy += ORDERING.immutableSortedCopy(input).get(0);
      }
    }
    return dummy;
  }

   */
  private static final Comparator<?> NATURAL_ORDER = Ordering.natural();

  private static final ImmutableSortedMap<Comparable<?>, Object> NATURAL_EMPTY_MAP =
      new ImmutableSortedMap<>(
          ImmutableSortedSet.emptySet(Ordering.natural()), ImmutableList.<Object>of());

  static <K, V> ImmutableSortedMap<K, V> emptyMap(Comparator<? super K> comparator) {
    if (Ordering.natural().equals(comparator)) {
      return of();

      implements TestSetGenerator<UnhashableObject> {}

  private static Ordering<String> createExplicitComparator(String[] elements) {
    // Collapse equal elements, which Ordering.explicit() doesn't support, while
    // maintaining the ordering by first occurrence.
    Set<String> elementsPlus = Sets.newLinkedHashSet();
    elementsPlus.add(BEFORE_FIRST);

        assertEquals("1.2.3-20090413X094722-2", ArtifactUtils.toSnapshotVersion("1.2.3-20090413X094722-2"));
    }

    /**
     * Tests that the ordering of the map resembles the ordering of the input collection of artifacts.
     */
    @Test
    void testArtifactMapByVersionlessIdOrdering() throws Exception {
        List<Artifact> list = new ArrayList<>();

      }
    }
    return dummy;
  }

  @Benchmark
  int ordering(int reps) {
    int dummy = 0;
    if (mutable) {
      for (int i = 0; i < reps; i++) {
        dummy += ORDERING.sortedCopy(input).get(0);
      }
    } else {
      for (int i = 0; i < reps; i++) {
        dummy += ORDERING.immutableSortedCopy(input).get(0);
      }
    }
    return dummy;
  }

 * @author Ben Yu
 * @since 12.0
 */
@GwtIncompatible
@J2ktIncompatible
@ElementTypesAreNonnullByDefault
public final class ArbitraryInstances {

  private static final Ordering<Field> BY_FIELD_NAME =
      new Ordering<Field>() {
        @Override
        public int compare(Field left, Field right) {
          return left.getName().compareTo(right.getName());
        }
      };

  /**

    testComparator(arbitrary, list);
  }

  public void testUsingToString() {
    Ordering<Object> ordering = Ordering.usingToString();
    testComparator(ordering, 1, 12, 124, 2);
    assertEquals("Ordering.usingToString()", ordering.toString());
    assertSame(ordering, reserialize(ordering));
  }

  // use an enum to get easy serializability

    testComparator(arbitrary, list);
  }

  public void testUsingToString() {
    Ordering<Object> ordering = Ordering.usingToString();
    testComparator(ordering, 1, 12, 124, 2);
    assertEquals("Ordering.usingToString()", ordering.toString());
    assertSame(ordering, reserialize(ordering));
  }

  // use an enum to get easy serializability