Elemental missing getWindow().newFormData()

[Daniel Mauricio Patino León]

Iam trying to implement a html5 file api + xmlhttrequest level 2  upload on my project.

But sems that Elemental is missing things of FormData and i can't send over XMLHttpRequest object.

How to construct a object of FormData ?

FormData formData = /*getWindow().newFormData() <- doesn't exist */null;

from http://dvcs.w3.org/hg/xhr/raw-file/tip/Overview.html#interface-formdata

interface FormData {
  void append(DOMString name, Blob value, optional DOMString filename);
  void append(DOMString name, DOMString value);
};

in the elemental one just 

formData.append(name, value, filename)

Where all parameters are strings.