code: public void start(DATA wizardData) {
  		if (!started) {
  			initHandlers();
  		}
  		for (WizardPage<DATA> page : pages) {
  			page.clear();
  			page.setWizardData(wizardData);
  		}
  		ListIterator<WizardPage<DATA>> iterator = pages.listIterator();
  		if (iterator.hasNext()) {
  			setCurrentPage(iterator.next());
  		}
  	}
docs: Starts or restarts this wizard by clearing all pages and presenting the first page to the user. This method
  should only be called after all pages have been added. After this method has been called, no more pages can be
  added.
  
  @param wizardData initial data