InputStream in = new ByteArrayInputStream(PRE_FILLED_100);
    byte[] b = ByteStreams.toByteArray(in, 100);
    assertThat(b).isEqualTo(PRE_FILLED_100);
  }

  public void testToByteArray_withSize_givenSmallerSize() throws IOException {
    InputStream in = new ByteArrayInputStream(PRE_FILLED_100);
    byte[] b = ByteStreams.toByteArray(in, 80);
    assertThat(b).isEqualTo(PRE_FILLED_100);
  }

                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);
  }

   */
  // 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.

  static <E extends @Nullable Object> Collection<E> filterCollection(
      Collection<E> collection, Predicate<? super E> predicate) {
    if (collection instanceof Set) {
      return Sets.filter((Set<E>) collection, predicate);
    } else {
      return Collections2.filter(collection, predicate);
    }
  }

  @Override
  public boolean containsKey(@CheckForNull Object key) {
    return asMap().get(key) != null;
  }

  @Override

 *
 * <p>{@code ByteSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a stream:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the
 *       returned stream is closed.
 *   <li><b>Convenience methods:</b> These are implementations of common operations that are

  private static class HasBoth extends TypeA implements TypeB {}

  @GwtIncompatible // Iterables.filter(Iterable, Class)
  public void testFilterByType_iterator() throws Exception {
    HasBoth hasBoth = new HasBoth();
    Iterable<TypeA> alist = Lists.newArrayList(new TypeA(), new TypeA(), hasBoth, new TypeA());
    Iterable<TypeB> blist = Iterables.filter(alist, TypeB.class);
    assertThat(blist).containsExactly(hasBoth).inOrder();
  }

 *
 * <p>{@code CharSource} provides two kinds of methods:
 *
 * <ul>
 *   <li><b>Methods that return a reader:</b> These methods should return a <i>new</i>, independent
 *       instance each time they are called. The caller is responsible for ensuring that the
 *       returned reader is closed.
 *   <li><b>Convenience methods:</b> These are implementations of common operations that are

  }

  /**
   * Loads {@link WillBeUnloadedException} in a separate {@code ClassLoader}, calls {@code
   * getChecked(future, WillBeUnloadedException.class)}, and returns the loader. The caller can then
   * test that the {@code ClassLoader} can still be GCed. The test amounts to a test that {@code
   * getChecked} holds no strong references to the class.
   */