code: protected InputStream readFiles() throws IOException {
      BufferedInputStream input = new BufferedInputStream(openFile(), BUFFER_SIZE);
      input.mark(100);
      try {
        return new XZInputStream(input);
      } catch (IOException e) {
        input.reset();
      }
      try {
        return new CompressorStreamFactory().createCompressorInputStream(input);
      } catch (CompressorException e) {
        input.reset();
      }
      try {
        return new ArchiveStreamFactory().createArchiveInputStream(input);
      } catch (ArchiveException e) {
        input.reset();
      }
      return input;
    }
docs: Returns the input stream of the trace data.