*
   * @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

  }

  // 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);
      ByteSource resliced = sliced.slice(0, size - 1);
      assertTrue(sliced.contentEquals(resliced));
    }

    ByteSource source = out.asByteSource();
    int chunk1 = Math.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();

        } else {
          return TO_BYTE_ARRAY_NEW_STRING.read(byteSource, cs);
        }
      }
    };

    abstract String read(ByteSource byteSource, Charset cs) throws IOException;
  }

  @Param({"UTF-8"})
  String charsetName;

  @Param ReadStrategy strategy;

  @Param({"10", "1024", "1048576"})
  int size;

  Charset charset;
  ByteSource data;

  @BeforeExperiment
  public void setUp() {

        } else {
          return TO_BYTE_ARRAY_NEW_STRING.read(byteSource, cs);
        }
      }
    };

    abstract String read(ByteSource byteSource, Charset cs) throws IOException;
  }

  @Param({"UTF-8"})
  String charsetName;

  @Param ReadStrategy strategy;

  @Param({"10", "1024", "1048576"})
  int size;

  Charset charset;
  ByteSource data;

  @BeforeExperiment
  public void setUp() {

  public void testConcat() throws IOException {
    ByteSource b1 = ByteSource.wrap(new byte[] {0, 1, 2, 3});
    ByteSource b2 = ByteSource.wrap(new byte[0]);
    ByteSource b3 = ByteSource.wrap(new byte[] {4, 5});

    byte[] expected = {0, 1, 2, 3, 4, 5};

    assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3)).read());
    assertArrayEquals(expected, ByteSource.concat(b1, b2, b3).read());

  public void testConcat() throws IOException {
    ByteSource b1 = ByteSource.wrap(new byte[] {0, 1, 2, 3});
    ByteSource b2 = ByteSource.wrap(new byte[0]);
    ByteSource b3 = ByteSource.wrap(new byte[] {4, 5});

    byte[] expected = {0, 1, 2, 3, 4, 5};

    assertArrayEquals(expected, ByteSource.concat(ImmutableList.of(b1, b2, b3)).read());
    assertArrayEquals(expected, ByteSource.concat(b1, b2, b3).read());

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

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

  private final TestByteSource byteSource;

  public TestCharSource(String content, TestOption... options) {
    this.byteSource = new TestByteSource(content.getBytes(UTF_8), options);
  }

  @Override
  public boolean wasStreamOpened() {
    return byteSource.wasStreamOpened();
  }

  @Override
  public boolean wasStreamClosed() {
    return byteSource.wasStreamClosed();
  }

  @Override