code: private InputStream prepareInputStream(InputStream stream) throws IOException
     {
        InputStream result;
        BufferedInputStream bis = new BufferedInputStream(stream);
        readHeaderProperties(bis);
        if (isCompressed())
        {
           result = new InflaterInputStream(bis);
        }
        else
        {
           result = bis;
        }
        return result;
     }
docs: If the file is compressed, handle this so that the stream is ready to read.
  
  @param stream input stream
  @return uncompressed input stream