for (K k : multimap().keySet()) {
      assertTrue(multimap().containsKey(k));
    }
  }

  public void testContainsKeyAgreesWithGet() {
    for (K k : sampleKeys()) {
      assertEquals(!multimap().get(k).isEmpty(), multimap().containsKey(k));
    }
  }

  public void testContainsKeyAgreesWithAsMap() {
    for (K k : sampleKeys()) {
      assertEquals(multimap().containsKey(k), multimap().asMap().containsKey(k));
    }
  }

        if (!member.isBinaryCompatible()) {

            removeAnnotationChanges(member);

            if ((member instanceof JApiClass) && member.getCompatibilityChanges().isEmpty()) {
                // A member of the class breaks binary compatibility.
                // That will be handled when the member is passed to `maybeViolation`.
                return null;
            }

          postponedRoutes += route
        } else {
          routes += route
        }
      }

      if (routes.isNotEmpty()) {
        break
      }
    }

    if (routes.isEmpty()) {
      // We've exhausted all Proxies so fallback to the postponed routes.
      routes += postponedRoutes
      postponedRoutes.clear()
    }

    return Selection(routes)
  }

  }

  @Override
  public @Nullable K higherKey(K key) {
    return delegate.higherKey(checkValid(key));
  }

  @Override
  public boolean isEmpty() {
    return delegate.isEmpty();
  }

  @Override
  public NavigableSet<K> keySet() {
    return navigableKeySet();
  }

  @Override
  public @Nullable Entry<K, V> lastEntry() {

    assertEquals(ImmutableMap.of("two", 2, "four", 4), filtered);

    filtered.clear();
    assertEquals(ImmutableMap.of("one", 1, "three", 3), unfiltered);
    assertTrue(filtered.isEmpty());
  }

  public void testFilteredEntriesIllegalPut() {
    Map<String, Integer> unfiltered = createUnfiltered();
    unfiltered.put("cat", 3);
    unfiltered.put("dog", 2);
    unfiltered.put("horse", 5);

    assertThat(table.get(null, 1)).isNull();
    assertThat(table.get(null, null)).isNull();
  }

  public void testIsEmpty() {
    assertTrue(table.isEmpty());
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertFalse(table.isEmpty());
  }

  public void testSize() {
    assertSize(0);
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    assertSize(3);
  }

        for (E e : set2) {
          if (!set1.contains(e)) {
            size++;
          }
        }
        return size;
      }

      @Override
      public boolean isEmpty() {
        return set1.isEmpty() && set2.isEmpty();
      }

      @Override
      public UnmodifiableIterator<E> iterator() {
        return new AbstractIterator<E>() {
          final Iterator<? extends E> itr1 = set1.iterator();

 * may be equal only if at least one of the bounds is closed:
 *
 * <ul>
 *   <li>{@code [a..a]} : a singleton range
 *   <li>{@code [a..a); (a..a]} : {@linkplain #isEmpty empty} ranges; also valid
 *   <li>{@code (a..a)} : <b>invalid</b>; an exception will be thrown
 * </ul>
 *
 * <h3>Warnings</h3>
 *
 * <ul>

  @CollectionSize.Require(ONE)
  public void testValuesIteratorRemove() {
    Iterator<V> valuesItr = multimap().values().iterator();
    valuesItr.next();
    valuesItr.remove();
    assertTrue(multimap().isEmpty());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    collection.clear();
    assertTrue("After clear(), a collection should be empty.", collection.isEmpty());
    assertEquals(0, collection.size());
    assertFalse(collection.iterator().hasNext());
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)