private void writeExecutables(UninstallData udata, JarOutputStream outJar) throws IOException {
   outJar.putNextEntry(new JarEntry("executables"));
   ObjectOutputStream execStream = new ObjectOutputStream(outJar);
   execStream.writeInt(udata.getExecutablesList().size());
   for (ExecutableFile file : udata.getExecutablesList()) {
     execStream.writeObject(file);
   }
   execStream.flush();
   outJar.closeEntry();
 }