* the offset at which the slice is supposed to start.
   */
  // TODO(cgdecker): Maybe add a test for this to ByteSourceTester
  public void testSlice_appendingAfterSlicing() throws IOException {
    // Source of length 5
    AppendableByteSource source = new AppendableByteSource(newPreFilledByteArray(5));

    // Slice it starting at offset 10.
    ByteSource slice = source.slice(10, 5);

    assertThrows(
        "expected IllegalArgumentException for call to slice with offset -1: " + source,
        IllegalArgumentException.class,
        () -> source.slice(-1, 0));

    assertThrows(
        "expected IllegalArgumentException for call to slice with length -1: " + source,
        IllegalArgumentException.class,
        () -> source.slice(0, -1));
  }

    assertThrows(
        "expected IllegalArgumentException for call to slice with offset -1: " + source,
        IllegalArgumentException.class,
        () -> source.slice(-1, 0));

    assertThrows(
        "expected IllegalArgumentException for call to slice with length -1: " + source,
        IllegalArgumentException.class,
        () -> source.slice(0, -1));
  }

   * the offset at which the slice is supposed to start.
   */
  // TODO(cgdecker): Maybe add a test for this to ByteSourceTester
  public void testSlice_appendingAfterSlicing() throws IOException {
    // Source of length 5
    AppendableByteSource source = new AppendableByteSource(newPreFilledByteArray(5));

    // Slice it starting at offset 10.
    ByteSource slice = source.slice(10, 5);

    CharSource concatenated = CharSource.concat(cycle);

    String expected = "abcdabcd";

    // read the first 8 chars manually, since there's no equivalent to ByteSource.slice
    // TODO(cgdecker): Add CharSource.slice?
    StringBuilder builder = new StringBuilder();
    Reader reader = concatenated.openStream(); // no need to worry about closing
    for (int i = 0; i < 8; i++) {

    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();
    assertNull(file);

    // Write data to go over the threshold
    if (chunk2 > 0) {
      if (JAVA_IO_TMPDIR.value().equals("/sdcard")) {

    CharSource concatenated = CharSource.concat(cycle);

    String expected = "abcdabcd";

    // read the first 8 chars manually, since there's no equivalent to ByteSource.slice
    // TODO(cgdecker): Add CharSource.slice?
    StringBuilder builder = new StringBuilder();
    Reader reader = concatenated.openStream(); // no need to worry about closing
    for (int i = 0; i < 8; i++) {

    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();
    assertNull(file);

    // Write data to go over the threshold
    if (chunk2 > 0) {
      if (JAVA_IO_TMPDIR.value().equals("/sdcard")) {

    assertEquals(ImmutableList.of(I18N), Resources.readLines(resource, Charsets.UTF_8));
  }

  public void testReadLines_withLineProcessor() throws IOException {
    URL resource = getClass().getResource("testdata/alice_in_wonderland.txt");
    LineProcessor<List<String>> collectAndLowercaseAndTrim =
        new LineProcessor<List<String>>() {
          List<String> collector = new ArrayList<>();

          @Override

    assertEquals(ImmutableList.of(I18N), Resources.readLines(resource, Charsets.UTF_8));
  }

  public void testReadLines_withLineProcessor() throws IOException {
    URL resource = getClass().getResource("testdata/alice_in_wonderland.txt");
    LineProcessor<List<String>> collectAndLowercaseAndTrim =
        new LineProcessor<List<String>>() {
          List<String> collector = new ArrayList<>();

          @Override