public function testInvalidate()
 {
     $do = new DataObjectTest_Fixture();
     $do->write();
     $do->delete();
     try {
         // Prohibit invalid object manipulation
         $do->delete();
         $do->write();
         $do->duplicate();
     } catch (Exception $e) {
         return;
     }
     $this->fail('Should throw an exception');
 }
 /**
  * @expectedException LogicException
  */
 public function testInvalidate()
 {
     $do = new DataObjectTest_Fixture();
     $do->write();
     $do->delete();
     $do->delete();
     // Prohibit invalid object manipulation
     $do->write();
     $do->duplicate();
 }