+ Ascii.truncate(BaseEncoding.base16().encode(bytes, offset, length), 30, "...")
          + ")";
    }
  }

  private static final class EmptyByteSource extends ByteArrayByteSource {

    static final EmptyByteSource INSTANCE = new EmptyByteSource();

    EmptyByteSource() {
      super(new byte[0]);
    }

    @Override
    public CharSource asCharSource(Charset charset) {
      checkNotNull(charset);