assertEquals(-1, Iterables.indexOf(list, Predicates.equalTo("jack")));
  }

  public void testIndexOf_withDuplicates() {
    List<String> list = Lists.newArrayList("mary", "bob", "bob", "bob", "sam");
    assertEquals(0, Iterables.indexOf(list, Predicates.equalTo("mary")));
    assertEquals(1, Iterables.indexOf(list, Predicates.equalTo("bob")));

 * 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
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizableWeakReference<T> extends WeakReference<T>
    implements FinalizableReference {
  /**

import com.google.errorprone.annotations.DoNotMock;

/**
 * Implemented by references that have code to run after garbage collection of their referents.
 *
 * @see FinalizableReferenceQueue
 * @author Bob Lee
 * @since 2.0
 */
@DoNotMock("Use an instance of one of the Finalizable*Reference classes")
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public interface FinalizableReference {
  /**

 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import javax.annotation.CheckForNull;

/**
 * Wraps an exception that occurred during a computation.
 *
 * @author Bob Lee
 * @since 2.0
 * @deprecated This exception is no longer thrown by {@code com.google.common}. Previously, it was
 *     thrown by {@link MapMaker} computing maps. When support for computing maps was removed from

 * 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
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizableWeakReference<T> extends WeakReference<T>
    implements FinalizableReference {
  /**

   * 1-bit characteristics.
   *
   * <p>There is more general code provided by Bob Jenkins to test arbitrarily sized characteristics
   * using the magic of gaussian elimination: http://burtleburtle.net/bob/crypto/findingc.html.
   */
  static void checkNo2BitCharacteristics(HashFunction function) {
    Random rand = new Random(0);
    int keyBits = 32;

 * java.util.WeakHashMap}, but note that it compares keys using object identity whereas {@code
 * WeakHashMap} uses {@link Object#equals}.
 *
 * @author Bob Lee
 * @author Charles Fry
 * @author Kevin Bourrillion
 * @since 2.0
 */
@J2ktIncompatible
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public final class MapMaker {

    try {
      Optional.of(null);
      fail();
    } catch (NullPointerException expected) {
    }
  }

  public void testFromNullable() {
    Optional<String> optionalName = Optional.fromNullable("bob");
    assertEquals("bob", optionalName.get());
  }

  public void testFromNullable_null() {
    // not promised by spec, but easier to test
    assertSame(Optional.absent(), Optional.fromNullable(null));
  }

    assertEquals(-1, Iterables.indexOf(list, Predicates.equalTo("jack")));
  }

  public void testIndexOf_withDuplicates() {
    List<String> list = Lists.newArrayList("mary", "bob", "bob", "bob", "sam");
    assertEquals(0, Iterables.indexOf(list, Predicates.equalTo("mary")));
    assertEquals(1, Iterables.indexOf(list, Predicates.equalTo("bob")));

 * Soft 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
 * @since 2.0
 */
@J2ktIncompatible
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public abstract class FinalizableSoftReference<T> extends SoftReference<T>
    implements FinalizableReference {
  /**