Map<String, String> map = Maps.newHashMap();
                    putEntries(map, entries);
                    map.putAll(ENTRIES_TO_FILTER);
                    map = Maps.filterEntries(map, FILTER_ENTRIES_1);
                    return Maps.filterEntries(map, FILTER_ENTRIES_2);
                  }
                })
            .named("Maps.filterEntries[Maps.filterEntries[Map, Predicate], Predicate]")

   */
  // TODO(kevinb): how can we omit that Iterables link when building gwt
  // javadoc?
  public static <E extends @Nullable Object> Collection<E> filter(
      Collection<E> unfiltered, Predicate<? super E> predicate) {
    if (unfiltered instanceof FilteredCollection) {
      // Support clear(), removeAll(), and retainAll() when filtering a filtered
      // collection.

   * <p><b>{@code Stream} equivalent:</b> {@link Stream#filter}.
   */
  public static <T extends @Nullable Object> Iterable<T> filter(
      final Iterable<T> unfiltered, final Predicate<? super T> retainIfTrue) {
    checkNotNull(unfiltered);
    checkNotNull(retainIfTrue);
    return new FluentIterable<T>() {
      @Override
      public Iterator<T> iterator() {
        return Iterators.filter(unfiltered.iterator(), retainIfTrue);
      }

  }

  private static final Predicate<Entry<Integer, String>> FILTER_GET_PREDICATE =
      new Predicate<Entry<Integer, String>>() {
        @Override
        public boolean apply(Entry<Integer, String> entry) {
          return !"badvalue".equals(entry.getValue()) && 55556 != entry.getKey();
        }
      };

  private static final Predicate<Entry<String, Integer>> FILTER_KEYSET_PREDICATE =
      new Predicate<Entry<String, Integer>>() {

   * removed from the underlying multiset.
   *
   * <p>The returned multiset isn't threadsafe or serializable, even if {@code unfiltered} is.
   *
   * <p>Many of the filtered multiset's methods, such as {@code size()}, iterate across every
   * element in the underlying multiset and determine which elements satisfy the filter. When a live

                  return map.entrySet().remove(o);
                }

                @Override
                public boolean removeIf(Predicate<? super Entry<String, String>> filter) {
                  return map.entrySet().removeIf(filter);
                }

                @Override
                public boolean containsAll(Collection<?> c) {
                  return map.entrySet().containsAll(c);
                }

  }

  interface X {}

  interface Y {}

  static class A implements X, Y {}

  static class B implements X, Y {}

  /**
   * This test passes if the {@code concat(…).filter(…).filter(…)} statement at the end compiles.
   * That statement compiles only if {@link FluentIterable#concat concat(aIterable, bIterable)}
   * returns a {@link FluentIterable} of elements of an anonymous type whose supertypes are the <a

                unfiltered.add("zzz");
                unfiltered.add("abc");
                return Collections2.filter(Collections2.filter(unfiltered, LENGTH_1), NOT_YYY_ZZZ);
              }
            })
        .named("Collections2.filter, filtered input")
        .withFeatures(
            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE,

                unfiltered.add("zzz");
                unfiltered.add("abc");
                return Collections2.filter(Collections2.filter(unfiltered, LENGTH_1), NOT_YYY_ZZZ);
              }
            })
        .named("Collections2.filter, filtered input")
        .withFeatures(
            CollectionFeature.SUPPORTS_ADD,
            CollectionFeature.SUPPORTS_REMOVE,

    assertThat(stream(FluentIterable.of(1, 2, 3)).filter(n -> n > 1)).containsExactly(2, 3);
  }

  @SuppressWarnings("deprecation")
  public void testStream_collection() {
    assertThat(stream(Arrays.asList())).isEmpty();
    assertThat(stream(Arrays.asList("a"))).containsExactly("a");
    assertThat(stream(Arrays.asList(1, 2, 3)).filter(n -> n > 1)).containsExactly(2, 3);
  }