protected void start(){
  checkState(executorService == null,"Cannot restart a Model");
  executorService=Executors.newSingleThreadExecutor();
  requestQueue=new SynchronousQueue<GenerationRequest>();
  CompilerRunner compilerRunner=new CompilerRunner();
  executorService.execute(compilerRunner);
  processingEnv=compilerRunner.getProcessingEnvironment();
}

protected void start ( ) { checkState ( executorService == null , "Cannot restart a Model" ) ; executorService = Executors . newSingleThreadExecutor ( ) ; requestQueue = new SynchronousQueue < GenerationRequest > ( ) ; CompilerRunner compilerRunner = new CompilerRunner ( ) ; executorService . execute ( compilerRunner ) ; processingEnv = compilerRunner . getProcessingEnvironment ( ) ; }
starts up the compiler thread and waits for it to return the processing environment .
