}

    /**
     * {@link IdentityHashMap}の新しいインスタンスを作成して返します。
     *
     * @param <K>
     *            {@link IdentityHashMap}のキーの型
     * @param <V>
     *            {@link IdentityHashMap}の値の型
     * @return {@link IdentityHashMap}の新しいインスタンス
     * @see IdentityHashMap#IdentityHashMap()
     */
    public static <K, V> IdentityHashMap<K, V> newIdentityHashMap() {

   * an element in the set. For example, {@code contains} returns {@code false} when passed an
   * object that equals a set member, but isn't the same instance. This behavior is similar to the
   * way {@code IdentityHashMap} handles key lookups.
   *
   * @since 8.0
   */
  public static <E extends @Nullable Object> Set<E> newIdentityHashSet() {
    return Collections.newSetFromMap(Maps.<E, Boolean>newIdentityHashMap());
  }

    HashMap<Object, Object> map = Maps.<Object, Object>newLinkedHashMap(original);
    assertEquals(original, map);
  }

  // Intentionally using IdentityHashMap to test creation.
  @SuppressWarnings("IdentityHashMapBoxing")
  public void testIdentityHashMap() {
    IdentityHashMap<Integer, Integer> map = Maps.newIdentityHashMap();
    assertEquals(Collections.emptyMap(), map);
  }

  public void testConcurrentMap() {

    HashMap<Object, Object> map = Maps.<Object, Object>newLinkedHashMap(original);
    assertEquals(original, map);
  }

  // Intentionally using IdentityHashMap to test creation.
  @SuppressWarnings("IdentityHashMapBoxing")
  public void testIdentityHashMap() {
    IdentityHashMap<Integer, Integer> map = Maps.newIdentityHashMap();
    assertEquals(Collections.emptyMap(), map);
  }

  public void testConcurrentMap() {

import com.google.j2objc.annotations.J2ObjCIncompatible;
import java.lang.ref.SoftReference;
import java.lang.ref.WeakReference;
import java.util.ConcurrentModificationException;
import java.util.IdentityHashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.annotation.CheckForNull;

/**