/* No aliasing on inverse operations. */
    assertThat(unmod.inverse()).isSameInstanceAs(unmod.inverse());
    assertThat(unmod.inverse().inverse()).isSameInstanceAs(unmod);

    /* Unmodifiable is a view. */
    mod.put(4, "four");
    assertEquals(true, unmod.get(4).equals("four"));
    assertEquals(true, unmod.inverse().get("four").equals(4));

            3, MODIFIABLE, newArrayList(1, 2), IteratorTester.KnownOrder.KNOWN_ORDER) {
          @Override
          protected Iterator<Integer> newTargetIterator() {
            return ImmutableList.of(1, 2).iterator();
          }
        };
    assertFailure(tester);
  }

  public void testUnknownOrder() {
    new IteratorTester<Integer>(

            3, MODIFIABLE, newArrayList(1, 2), IteratorTester.KnownOrder.KNOWN_ORDER) {
          @Override
          protected Iterator<Integer> newTargetIterator() {
            return ImmutableList.of(1, 2).iterator();
          }
        };
    assertFailure(tester);
  }

  public void testUnknownOrder() {
    new IteratorTester<Integer>(

    /**
     * Gets the packages/types to import from the parent realm.
     *
     * @return The modifiable list of packages/types to import from the parent realm, never {@code null}.
     */
    List<String> getParentImports();

    /**
     * Gets the packages/types to import from foreign realms.
     *
     * @return The modifiable map of packages/types to import from foreign realms, never {@code null}.
     */

import static com.google.common.collect.Sets.newHashSet;
import static com.google.common.collect.testing.Helpers.mapEntry;
import static com.google.common.collect.testing.IteratorFeature.MODIFIABLE;
import static com.google.common.truth.Truth.assertThat;
import static java.util.Arrays.asList;

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;

 * caution if mutable objects are used as keys in a {@code Multimap}.
 *
 * <p>All methods that modify the multimap are optional. The view collections returned by the
 * multimap may or may not be modifiable. Any modification method that is not supported will throw
 * {@link UnsupportedOperationException}.
 *
 * <p>See the Guava User Guide article on <a href=

 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly if the last write <i>happens-before</i> any reads. To allow

 * caution if mutable objects are used as keys in a {@code Multimap}.
 *
 * <p>All methods that modify the multimap are optional. The view collections returned by the
 * multimap may or may not be modifiable. Any modification method that is not supported will throw
 * {@link UnsupportedOperationException}.
 *
 * <p>See the Guava User Guide article on <a href=

 * value and the old value.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>The lists returned by {@link #get}, {@link #removeAll}, and {@link #replaceValues} all
 * implement {@link java.util.RandomAccess}.
 *

 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly if the last write <i>happens-before</i> any reads. To allow