if (mDestDir == null) throw new IllegalStateException("destdir not set");
if (mOutputDir == null) throw new IllegalStateException("destdir not set");
  public void doCodegen() throws IOException {    if (mDestDir == null) throw new IllegalStateException("destdir not set");    while(mClassesLeftTodo.size() > 0) {      JClass clazz = (JClass)mClassesLeftTodo.get(0);      mClassesLeftTodo.remove(0);      mClassesDone.add(clazz);      doCodegen(clazz);    }  }