QTabWidget stylesheet properties

Hi there! :)

I can't to use the property tabPosition :S and maybe I'm doing anything worng:

Code:

---

QTabWidget[tabPosition="North"]::pane { /* The tab widget frame */
border-top: 2px solid #C2C7CB;
position: absolute;
top: -2px;
border-color: black;
}

---

I need to identify tab position, North, West... etc, and use different border-image. The before code is for to force to change anything of my current stylesheet but... nothing happend :(

Thanks in advance!