Selectors on document fragment

[Munawwar]

A simple selector such as the following doesn't seem to work:

var df = document.createDocumentFragment(),
    div = document.createElement('div');
div.className = 'btn';
df.appendChild(div);

Sizzle('.btn', df).length; //is 0
df.querySelectorAll('.btn').length; //is 1

I used dist/sizzle.min.js from latest commit (a9361f6) to test the above.

[Munawwar]

If you are wondering the use case for this feature: For unit testing HTML output. - I could get rid of code like this