public void testConcurrentAdvance() throws Exception {
    FakeTicker ticker = new FakeTicker();

    int numberOfThreads = 64;
    runConcurrentTest(
        numberOfThreads,
        () -> {
          // adds two nanoseconds to the ticker
          ticker.advance(1L);
          Thread.sleep(10);
          ticker.advance(1L);
          return null;
        });

    assertEquals(numberOfThreads * 2, ticker.read());
  }

import java.lang.reflect.Type;
import java.util.Arrays;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tester of subtyping relationships between two types.
 *
 * <p>Tests should inherit from this class, and declare subtyping relationship with public methods
 * annotated by {@link TestSubtype}.
 *

   * Multimaps#asMap(SetMultimap)} instead.
   */
  @Override
  Map<K, Collection<V>> asMap();

  /**
   * Compares the specified object to this multimap for equality.
   *
   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.
   * Equality does not depend on the ordering of keys or values.
   *

   */
  @Override
  Set<V> values();

  /**
   * Returns the inverse view of this bimap, which maps each of this bimap's values to its
   * associated key. The two bimaps are backed by the same data; any changes to one will appear in
   * the other.
   *
   * <p><b>Note:</b> There is no guaranteed correspondence between the iteration order of a bimap
   * and that of its inverse.

  // Object methods

  /**
   * {@inheritDoc}
   *
   * <p>This implementation returns {@code true} if {@code object} is a multiset of the same size
   * and if, for each element, the two multisets have the same count.
   */
  @Override
  public final boolean equals(@Nullable Object object) {
    return Multisets.equalsImpl(this, object);
  }

  /**
   * {@inheritDoc}
   *

   * Multimaps#asMap(SetMultimap)} instead.
   */
  @Override
  Map<K, Collection<V>> asMap();

  /**
   * Compares the specified object to this multimap for equality.
   *
   * <p>Two {@code SetMultimap} instances are equal if, for each key, they contain the same values.
   * Equality does not depend on the ordering of keys or values.
   *

 *       to <i>some</i> degree to make this unlikely. (Without this condition, a function that
 *       always returns zero could be called a hash function. It is not.)
 * </ul>
 *
 * <p>Summarizing the last two points: "equal yield equal <i>always</i>; unequal yield unequal
 * <i>often</i>." This is the most important characteristic of all hash functions.
 *
 * <h3>Desirable properties</h3>
 *

     * Return the IP address of this address as a 32 bit integer.
     */

    @Override
    public int hashCode() {
        return addr.hashCode();
    }

    /**
     * Compare two addresses for equality. Two <code>UniAddress</code>s are equal
     * if they are both <code>UniAddress</code>' and refer to the same IP address.
     */
    @Override
    public boolean equals(final Object obj) {

    @Override
    public SampleElements<Entry<String, Collection<Integer>>> samples() {
      return new SampleElements<>(
          mapEntry("one", ImmutableSet.of(10000)),
          mapEntry("two", ImmutableSet.of(-2000)),
          mapEntry("three", ImmutableSet.of(300)),
          mapEntry("four", ImmutableSet.of(-40)),
          mapEntry("five", ImmutableSet.of(5)));
    }

    @Override

                return wrap(delegate);
              }
            });
  }

  public void testEquals() {
    Multiset<String> set1 = ImmutableMultiset.of("one");
    Multiset<String> set2 = ImmutableMultiset.of("two");
    new EqualsTester()
        .addEqualityGroup(set1, wrap(set1), wrap(set1))
        .addEqualityGroup(set2, wrap(set2))
        .testEquals();
  }