Bars plot, x label (two levels) rotation

HoloViews
,
#1

Hi, I’m having some trouble figuring out how to rotate the second level x-label test.
As you can see here:

image
image1062×607 21.6 KB

The second level x-labels are unreadable, and I would like to rotate them (45\90 degrees)
Is this achievable via HoloViews?