TextSpanner + \break

[David Bobroff]

I want a TextSpanner to go over a line break.  I'm not getting it. 
Here's a short piec of *.ly code:

%%%%%%%%%%%%%%%%%%%%%%
\version "2.11.42"

#'ly:set-point-and-click ##f
stuff = \relative {
        \override TextSpanner #'style = #'dotted-line
	\override TextSpanner #'bound-details #'left #'text = \markup{\dynamic 
"mf"}
	\override TextSpanner #'bound-details #'right #'text = 
\markup{\dynamic "pp"}	
        \override TextSpanner #'breakable = ##t
        c1 \startTextSpan
        \break
        c1 \stopTextSpan
        }

        
\score {
        \stuff
}
%%%%%%%%%%%%%%%%%%%

I found a reference in the docs to TextSpanners and line breaks 
(1.8.3.2) but I don't see an example like what I want to do.

What I would like to have in the above snippet is for the "pp" to be 
printed on the second line.

-David