unfiltered.put("one", 1);
    unfiltered.put("two", 2);
    unfiltered.put("three", 3);
    unfiltered.put("four", 4);
    Map<String, Integer> filtered = Maps.filterValues(unfiltered, EVEN);
    assertEquals(ImmutableMap.of("one", 1, "two", 2, "three", 3, "four", 4), unfiltered);
    assertEquals(ImmutableMap.of("two", 2, "four", 4), filtered);

    filtered.clear();

    unfiltered.put("foo", 55556);
    unfiltered.put("badkey", 1);
    unfiltered.put("foo", 1);
    Multimap<String, Integer> keyFiltered = filterKeys(unfiltered, KEY_PREDICATE);
    Multimap<String, Integer> filtered = filterValues(keyFiltered, VALUE_PREDICATE);
    assertEquals(1, filtered.size());
    assertTrue(filtered.containsEntry("foo", 1));

                List<String> unfiltered = newArrayList();
                unfiltered.add("yyy");
                unfiltered.addAll(ImmutableList.copyOf(elements));
                unfiltered.add("zzz");
                unfiltered.add("abc");
                return Collections2.filter(Collections2.filter(unfiltered, LENGTH_1), NOT_YYY_ZZZ);
              }
            })

    final Collection<E> unfiltered;
    final Predicate<? super E> predicate;

    FilteredCollection(Collection<E> unfiltered, Predicate<? super E> predicate) {
      this.unfiltered = unfiltered;
      this.predicate = predicate;
    }

    FilteredCollection<E> createCombined(Predicate<? super E> newPredicate) {
      return new FilteredCollection<>(unfiltered, Predicates.and(predicate, newPredicate));
    }

  final Multimap<K, V> unfiltered;
  final Predicate<? super Entry<K, V>> predicate;

  FilteredEntryMultimap(Multimap<K, V> unfiltered, Predicate<? super Entry<K, V>> predicate) {
    this.unfiltered = checkNotNull(unfiltered);
    this.predicate = checkNotNull(predicate);
  }

  @Override
  public Multimap<K, V> unfiltered() {
    return unfiltered;
  }

  @Override

    unfiltered.put("foo", 55556);
    unfiltered.put("badkey", 1);
    unfiltered.put("foo", 1);
    Multimap<String, Integer> keyFiltered = filterKeys(unfiltered, KEY_PREDICATE);
    Multimap<String, Integer> filtered = filterValues(keyFiltered, VALUE_PREDICATE);
    assertEquals(1, filtered.size());
    assertTrue(filtered.containsEntry("foo", 1));

        for (int i = 0; i < 10; i++) {
          assertEquals(unfiltered.lower(i), filtered.lower(i));
          assertEquals(unfiltered.floor(i), filtered.floor(i));
          assertEquals(unfiltered.ceiling(i), filtered.ceiling(i));
          assertEquals(unfiltered.higher(i), filtered.higher(i));
        }
      }
    }
  }

  private FilteredCollectionsTestUtil() {}

    return (unfiltered instanceof AbstractFilteredMap)
        ? filterFiltered((AbstractFilteredMap<K, V>) unfiltered, entryPredicate)
        : new FilteredEntryMap<K, V>(checkNotNull(unfiltered), entryPredicate);
  }

  /**
   * Returns a sorted map containing the mappings in {@code unfiltered} that satisfy a predicate.
   * The returned map is a live view of {@code unfiltered}; changes to one affect the other.
   *

    return (unfiltered instanceof AbstractFilteredMap)
        ? filterFiltered((AbstractFilteredMap<K, V>) unfiltered, entryPredicate)
        : new FilteredEntryMap<K, V>(checkNotNull(unfiltered), entryPredicate);
  }

  /**
   * Returns a sorted map containing the mappings in {@code unfiltered} that satisfy a predicate.
   * The returned map is a live view of {@code unfiltered}; changes to one affect the other.
   *

  final Multimap<K, V> unfiltered;
  final Predicate<? super K> keyPredicate;

  FilteredKeyMultimap(Multimap<K, V> unfiltered, Predicate<? super K> keyPredicate) {
    this.unfiltered = checkNotNull(unfiltered);
    this.keyPredicate = checkNotNull(keyPredicate);
  }

  @Override
  public Multimap<K, V> unfiltered() {
    return unfiltered;
  }

  @Override