* 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

  public void testByteSource_size_ofDirectory() throws IOException {
    try (FileSystem fs = Jimfs.newFileSystem(Configuration.unix())) {
      Path dir = fs.getPath("dir");
      Files.createDirectory(dir);

      ByteSource source = MoreFiles.asByteSource(dir);

      assertThat(source.sizeIfKnown()).isAbsent();

      assertThrows(IOException.class, () -> source.size());
    }
  }

   */
  public static ByteSource asByteSource(Path path, OpenOption... options) {
    return new PathByteSource(path, options);
  }

  @IgnoreJRERequirement // *should* be redundant with the one on MoreFiles itself
  private static final class PathByteSource extends
      ByteSource
  {

    private static final LinkOption[] FOLLOW_LINKS = {};

   * equivalent to providing the {@link StandardOpenOption#READ READ} option.
   */
  public static ByteSource asByteSource(Path path, OpenOption... options) {
    return new PathByteSource(path, options);
  }

  private static final class PathByteSource extends
      ByteSource
  {

    private static final LinkOption[] FOLLOW_LINKS = {};

    private final Path path;

    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++) {