assertEquals(STRING.length(), source.copyTo(sink));
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
    assertTrue(sink.wasStreamOpened() && sink.wasStreamClosed());

    assertEquals(STRING, sink.getString());
  }

  public void testRead_toString() throws IOException {
    assertEquals(STRING, source.read());
    assertTrue(source.wasStreamOpened() && source.wasStreamClosed());
  }

 * interface easier to implement for certain types of data sources.
 *
 * <p>{@code Iterator} requires its implementations to support querying the end-of-data status
 * without changing the iterator's state, using the {@link #hasNext} method. But many data sources,
 * such as {@link java.io.Reader#read()}, do not expose this information; the only way to discover

@ElementTypesAreNonnullByDefault
public final class Resources {
  private Resources() {}

  /**
   * Returns a {@link ByteSource} that reads from the given URL.
   *
   * @since 14.0
   */
  public static ByteSource asByteSource(URL url) {
    return new UrlByteSource(url);
  }

  /** A byte source that reads from a URL using {@link URL#openStream()}. */
  private static final class UrlByteSource extends ByteSource {

        IllegalArgumentException.class,
        () -> source.slice(0, -1));
  }

  // Test that you can not expand the readable data in a previously sliced ByteSource.
  public void testSlice_constrainedRange() throws IOException {
    long size = source.read().length;
    if (size >= 2) {
      ByteSource sliced = source.slice(1, size - 2);
      assertEquals(size - 2, sliced.read().length);

    assertTrue(Arrays.equals(data, source.read()));
    out.reset();
  }

  public void testReset() throws Exception {
    byte[] data = newPreFilledByteArray(100);
    FileBackedOutputStream out = new FileBackedOutputStream(Integer.MAX_VALUE);
    ByteSource source = out.asByteSource();

    out.write(data);
    assertTrue(Arrays.equals(data, source.read()));

    out.reset();

      exponent[i] = randomExponent();
      factorial[i] = RANDOM_SOURCE.nextInt(50);
      binomial[i] = RANDOM_SOURCE.nextInt(factorial[i] + 1);
      positive[i] = randomPositiveBigInteger(Integer.SIZE - 1).intValue();
      nonnegative[i] = randomNonNegativeBigInteger(Integer.SIZE - 1).intValue();
      ints[i] = RANDOM_SOURCE.nextInt();
    }
  }

  @Benchmark
  int pow(int reps) {
    int tmp = 0;

<module>
<source path="">
  <!-- Hack to keep collect from hiding collect.testing supersource: -->
  <exclude name="**/testing/**"/>
</source>

<!--
    We used to set this only for packages that had manual supersource. That
    worked everywhere that I know of except for one place: when running the GWT
    util.concurrent tests under Guava.

    The problem is that GWT responds poorly to two .gwt.xml files in the same

<module>
<source path="">
  <!-- Hack to keep collect from hiding collect.testing supersource: -->
  <exclude name="**/testing/**"/>
</source>

<!--
    We used to set this only for packages that had manual supersource. That
    worked everywhere that I know of except for one place: when running the GWT
    util.concurrent tests under Guava.

    The problem is that GWT responds poorly to two .gwt.xml files in the same

<module>
<source path="">
  <!-- Hack to keep collect from hiding collect.testing supersource: -->
  <exclude name="**/testing/**"/>
</source>

<!--
    We used to set this only for packages that had manual supersource. That
    worked everywhere that I know of except for one place: when running the GWT
    util.concurrent tests under Guava.

    The problem is that GWT responds poorly to two .gwt.xml files in the same

    Iterator<Integer> source = Iterators.singletonIterator(1);
    try {
      Iterators.partition(source, 0);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testPartition_empty() {
    Iterator<Integer> source = Iterators.emptyIterator();
    Iterator<List<Integer>> partitions = Iterators.partition(source, 1);
    assertFalse(partitions.hasNext());
  }