*   <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

        && builder.getValueStrength() == Strength.WEAK) {
      return new MapMakerInternalMap<>(builder, StrongKeyWeakValueEntry.Helper.instance());
    }
    if (builder.getKeyStrength() == Strength.WEAK
        && builder.getValueStrength() == Strength.STRONG) {
      return new MapMakerInternalMap<>(builder, WeakKeyStrongValueEntry.Helper.instance());
    }
    if (builder.getKeyStrength() == Strength.WEAK && builder.getValueStrength() == Strength.WEAK) {

      this.strong = true;
      return this;
    }

    /**
     * Instructs the {@link InternerBuilder} to build a weak interner.
     *
     * @see Interners#newWeakInterner()
     */
    @CanIgnoreReturnValue
    @GwtIncompatible // java.lang.ref.WeakReference
    public InternerBuilder weak() {
      this.strong = false;
      return this;
    }

    /**

import java.util.concurrent.ConcurrentMap;
import org.jspecify.annotations.Nullable;

/**
 * A builder of {@link ConcurrentMap} instances that can have keys or values automatically wrapped
 * in {@linkplain WeakReference weak} references.
 *
 * <p>Usage example:
 *
 * {@snippet :
 * ConcurrentMap<Request, Stopwatch> timers = new MapMaker()
 *     .concurrencyLevel(4)
 *     .weakKeys()
 *     .makeMap();
 * }
 *

import com.google.common.annotations.J2ktIncompatible;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import org.jspecify.annotations.Nullable;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee

import com.google.common.annotations.J2ktIncompatible;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import org.jspecify.annotations.Nullable;

/**
 * Weak reference with a {@code finalizeReferent()} method which a background thread invokes after
 * the garbage collector reclaims the referent. This is a simpler alternative to using a {@link
 * ReferenceQueue}.
 *
 * @author Bob Lee

    assertThrows(NoSuchElementException.class, iter::next);
    assertThrows(NoSuchElementException.class, iter::peek);
  }


  @J2ktIncompatible // weak references, details of GC
  @GwtIncompatible // weak references
  public void testFreesNextReference() {
    Iterator<Object> itr =
        new AbstractIterator<Object>() {
          @Override
          public Object computeNext() {

    assertThrows(NoSuchElementException.class, iter::next);
    assertThrows(NoSuchElementException.class, iter::peek);
  }


  @J2ktIncompatible // weak references, details of GC
  @GwtIncompatible // weak references
  public void testFreesNextReference() {
    Iterator<Object> itr =
        new AbstractIterator<Object>() {
          @Override
          public Object computeNext() {

    // Using @Weak is necessary to avoid retain-cycles between Node instances on iOS,
    // which would cause memory leaks when non-empty HashBiMap with cyclic Node
    // instances is deallocated.
    @Nullable Node<K, V> nextInKToVBucket;
    @Weak @Nullable Node<K, V> nextInVToKBucket;

    @Weak @Nullable Node<K, V> nextInKeyInsertionOrder;

#else
#define TF_CAPI_EXPORT __declspec(dllimport)
#endif  // TF_COMPILE_LIBRARY
#else
#ifdef TF_CAPI_WEAK
#define TF_CAPI_EXPORT \
  __attribute__((visibility("default"))) __attribute((weak))
#else
#define TF_CAPI_EXPORT __attribute__((visibility("default")))
#endif  // TF_CAPI_WEAK
#endif  // _WIN32
#endif  // SWIG

// TF_Bool is the C API typedef for unsigned char, while TF_BOOL is