@ParametricNullness private final T reference;

    private Wrapper(Equivalence<? super @NonNull T> equivalence, @ParametricNullness T reference) {
      this.equivalence = checkNotNull(equivalence);
      this.reference = reference;
    }

    /** Returns the (possibly null) reference wrapped by this instance. */
    @ParametricNullness
    public T get() {
      return reference;
    }

    /**

    @ParametricNullness private final T reference;

    private Wrapper(Equivalence<? super @NonNull T> equivalence, @ParametricNullness T reference) {
      this.equivalence = checkNotNull(equivalence);
      this.reference = reference;
    }

    /** Returns the (possibly null) reference wrapped by this instance. */
    @ParametricNullness
    public T get() {
      return reference;
    }

    /**

	// check relations
	relations := []Relation{
		{
			Name: "Account", Type: schema.HasOne, Schema: "User", FieldSchema: "Account",
			References: []Reference{{"ID", "User", "UserID", "Account", "", true}},
		},
		{
			Name: "Pets", Type: schema.HasMany, Schema: "User", FieldSchema: "Pet",
			References: []Reference{{"ID", "User", "UserID", "Pet", "", true}},
		},
		{
			Name: "Toys", Type: schema.HasMany, Schema: "User", FieldSchema: "Toy",

public class EqualsTesterTest extends TestCase {
  private ValidTestObject reference;
  private EqualsTester equalsTester;
  private ValidTestObject equalObject1;
  private ValidTestObject equalObject2;
  private ValidTestObject notEqualObject1;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    reference = new ValidTestObject(1, 2);
    equalsTester = new EqualsTester();

/**
 * An immutable object that may contain a non-null reference to another object. Each instance of
 * this type either contains a non-null reference, or contains nothing (in which case we say that
 * the reference is "absent"); it is never said to "contain {@code null}".
 *
 * <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable {@code T}

      return created;
    }

    // N.B. Draining the queue is only necessary to ensure that we don't accumulate empty references
    // in the array. We could skip this if we decide we don't care about holding on to Reference
    // objects indefinitely.
    private void drainQueue() {
      Reference<? extends L> ref;
      while ((ref = queue.poll()) != null) {

        map.put(keyOne, valueOne);
        InternalEntry<Object, Object, ?> entry = segment.getEntry(keyOne, hashOne);

        @SuppressWarnings("unchecked")
        Reference<Object> reference = (Reference<Object>) entry;
        reference.enqueue();

        map.put(keyTwo, valueTwo);
        assertFalse(map.containsKey(keyOne));
        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));

        map.put(keyOne, valueOne);
        InternalEntry<Object, Object, ?> entry = segment.getEntry(keyOne, hashOne);

        @SuppressWarnings("unchecked")
        Reference<Object> reference = (Reference<Object>) entry;
        reference.enqueue();

        map.put(keyTwo, valueTwo);
        assertFalse(map.containsKey(keyOne));
        assertFalse(map.containsValue(valueOne));
        assertNull(map.get(keyOne));

      Preconditions.checkState(valueRef instanceof Reference);
      Reference<V> ref = (Reference<V>) valueRef;
      if (ref != null) {
        ref.clear();
      }
    }
  }

  /**
   * Poke into the Cache internals to simulate garbage collection of the given key. This assumes
   * that the given entry is a weak or soft reference, and throws an IllegalStateException if that
   * assumption does not hold.

   *   <li>clearing weak references to unreachable referents
   *   <li>enqueuing weak references to unreachable referents in their reference queue
   * </ul>
   */
  @DoNotMock("Implement with a lambda")
  public interface FinalizationPredicate {
    boolean isDone();
  }

  /**
   * Waits until the given weak reference is cleared, invoking the garbage collector as necessary to