issues with flash.utils.getDefinitionByName

I’m having some issues with [SIZE=2]flash.utils.getDefinitionByName functions. If I don’t declare dummy variable it throws Error #1065: Variable *** is not defined. Here’s example code:[/SIZE]

private function example():void {
  // var dummy:Example;
  // if I don't add line above compiler throws error
  var _className:String = "correct.path.Example";
  var _class:Class = getDefinitionByName(_className) as Class;
  var instance:* = new _class();
}

[SIZE=2]Anyone knows why this isn’t working without dummy variable? I’m guessing it’s some compiler issue…[/SIZE]