*
   * @param sources the sources to concatenate
   * @return a {@code ByteSource} containing the concatenated data
   * @since 15.0
   */
  public static ByteSource concat(Iterable<? extends ByteSource> sources) {
    return new ConcatenatedByteSource(sources);
  }

  /**
   * Concatenates multiple {@link ByteSource} instances into a single source. Streams returned from

    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {

    joinHelper(1, 1, 1, 1, 1, 1, 1, 1);
    joinHelper(1, 0, 1, 0, 1, 0, 1, 0);
  }

  public void testOnlyOneOpen() throws Exception {
    ByteSource source = newByteSource(0, 50);
    int[] counter = new int[1];
    ByteSource checker =
        new ByteSource() {
          @Override
          public InputStream openStream() throws IOException {
            if (counter[0]++ != 0) {

    ByteSource source = out.asByteSource();
    int chunk1 = min(dataSize, fileThreshold);
    int chunk2 = dataSize - chunk1;

    // Write just enough to not trip the threshold
    if (chunk1 > 0) {
      write(out, data, 0, chunk1, singleByte);
      assertTrue(ByteSource.wrap(data).slice(0, chunk1).contentEquals(source));
    }
    File file = out.getFile();

 * the License.
 */

/**
 * Utility methods and classes for I/O; for example input streams, output streams, readers, writers,
 * and files.
 *
 * <p>At the core of this package are the Source/Sink types: {@link ByteSource ByteSource}, {@link
 * CharSource CharSource}, {@link ByteSink ByteSink} and {@link CharSink CharSink}. They are
 * factories for I/O streams that provide many convenience methods that handle both opening and
 * closing streams for you.

    ByteSource source = out.asByteSource();
    int chunk1 = min(dataSize, fileThreshold);
    int chunk2 = dataSize - chunk1;

    // Write just enough to not trip the threshold
    if (chunk1 > 0) {
      write(out, data, 0, chunk1, singleByte);
      assertTrue(ByteSource.wrap(data).slice(0, chunk1).contentEquals(source));
    }
    File file = out.getFile();

    @Override
    public void tearDown() throws IOException {}
  }

  private static class ByteArraySourceFactory implements ByteSourceFactory {

    @Override
    public ByteSource createSource(byte[] bytes) throws IOException {
      return ByteSource.wrap(bytes);
    }

    @Override
    public byte[] getExpected(byte[] bytes) {
      return bytes;
    }

    @Override

  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 {

    private final URL url;

          .put(FloatBuffer.class, FloatBuffer.allocate(0))
          .put(DoubleBuffer.class, DoubleBuffer.allocate(0))
          .put(File.class, new File(""))
          .put(ByteSource.class, ByteSource.empty())
          .put(CharSource.class, CharSource.empty())
          .put(ByteSink.class, NullByteSink.INSTANCE)
          .put(CharSink.class, NullByteSink.INSTANCE.asCharSink(UTF_8))

 * be an empty line at the end if the contents are terminated with a line separator.
 *
 * <p>Any {@link ByteSource} containing text encoded with a specific {@linkplain Charset character
 * encoding} may be viewed as a {@code CharSource} using {@link ByteSource#asCharSource(Charset)}.
 *
 * <p><b>Note:</b> In general, {@code CharSource} is intended to be used for "file-like" sources