public function __construct(View_Manager $view_manager)
 {
     parent::__construct($view_manager);
     $this->_session_var = 'testform';
     $this->template = 'testform/default';
     // default template
 }
 public function __construct(View_Manager $view_manager)
 {
     parent::__construct($view_manager);
     $this->_session_var = 'tbsvv';
     $this->_spam = null;
     $this->_attributes->register('hidden');
     // expected value of "hidden" form element
 }