Allow locking of individual document sections when editing sections

I divide the whole page into several sections with "1.1" tag, but when there are several different users editing different sections of this page, xwiki will indicates that someone locks the page. For example:
(1) Test page is divided into 2 sections like below:
1.1 Section 1
content of section 1

1.2 Section 2
content of section 2

(2) Alice log into xwiki and navigate to test page, and click the editing icon right of head title "Section 1" to edit section 1
(3) During Alice's editing period, Scott log into xwiki and navigate to test page, and click editing icon right of head title "Section 2" to edit section 2. At this time, xwiki will show a page to tell Scott that "Test page is locked by Alice", and Scott has to choose whether to force editing this page or not.

I think the lock should not be applied to the whole page because Alice was just editing section 1 of the test page. Instead, Scott should be able to edit section 2 without any conflict.

And I've also post this issue to mail list, http://www.nabble.com/forum/ViewPost.jtp?post=11805713&framed=y