Multimap<String, Integer> filtered = filterValues(keyFiltered, VALUE_PREDICATE);
    assertEquals(1, filtered.size());
    assertTrue(filtered.containsEntry("foo", 1));
    assertTrue(filtered.keySet().retainAll(asList("cat", "dog")));
    assertEquals(0, filtered.size());
  }

  // TODO(jlevy): Many more tests needed.

    Map<String, Integer> map = ImmutableSortedMap.of("one", 1, "two", 2, "three", 3);
    SerializableTester.reserializeAndAssert(map.entrySet());
    SerializableTester.reserializeAndAssert(map.keySet());
    assertEquals(
        new ArrayList<>(map.values()),
        new ArrayList<>(SerializableTester.reserialize(map.values())));
  }

    Map<String, Integer> map = ImmutableSortedMap.of("one", 1, "two", 2, "three", 3);
    SerializableTester.reserializeAndAssert(map.entrySet());
    SerializableTester.reserializeAndAssert(map.keySet());
    assertEquals(
        new ArrayList<>(map.values()),
        new ArrayList<>(SerializableTester.reserialize(map.values())));
  }

 * order to {@code [key2, key1]}. The {@link #entries()} iterator returns mutable map entries, and
 * {@link #replaceValues} attempts to preserve iteration order as much as possible.
 *
 * <p>The collections returned by {@link #keySet()} and {@link #asMap()} iterate through the keys in
 * the order they were first added to the multimap. Similarly, {@link #get}, {@link #removeAll}, and

        keys = result = Multisets.unmodifiableMultiset(delegate.keys());
      }
      return result;
    }

    @Override
    public Set<K> keySet() {
      Set<K> result = keySet;
      if (result == null) {
        keySet = result = Collections.unmodifiableSet(delegate.keySet());
      }
      return result;
    }

    @Override
    public boolean put(@ParametricNullness K key, @ParametricNullness V value) {

        keys = result = Multisets.unmodifiableMultiset(delegate.keys());
      }
      return result;
    }

    @Override
    public Set<K> keySet() {
      Set<K> result = keySet;
      if (result == null) {
        keySet = result = Collections.unmodifiableSet(delegate.keySet());
      }
      return result;
    }

    @Override
    public boolean put(@ParametricNullness K key, @ParametricNullness V value) {

    for (Object entry : map.entrySet()) {
      retVal += entry.hashCode();
    }
    return (int) retVal;
  }

  @Benchmark
  public int keyIterate() {
    long retVal = 0;
    for (Object key : map.keySet()) {
      retVal += key.hashCode();
    }
    return (int) retVal;
  }

Sie sind jedoch nicht auf die Verwendung von bestimmten Datenmodellen, Klassen, oder Typen beschränkt.

Möchten Sie eine `id` und eine `email` und keinen `username` in Ihrem Modell haben? Kein Problem. Sie können dieselben Tools verwenden.

      this.upperBound = upperBound;
      checkArgument(
          lowerBound == null || upperBound == null || compare(lowerBound, upperBound) <= 0);
    }

    @Override
    public SortedSet<C> keySet() {
      return new Maps.SortedKeySet<>(this);
    }

    @Override
    public Comparator<? super C> comparator() {
      return columnComparator();
    }

    int compare(Object a, Object b) {

  @CollectionSize.Require(SEVERAL)
  public void testClearConcurrentWithKeySetIteration() {
    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<K> iterator = getMap().keySet().iterator();
          getMap().clear();
          iterator.next();
        });
  }

  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
  @CollectionSize.Require(SEVERAL)