+ \override TextSpanner #'style = #'line
+ \override TextSpanner #'(bound-details right arrow) = ##t
+ \override TextSpanner #'(bound-details left text) = #"fof"
+ \override TextSpanner #'(bound-details right text) = #"gag"
+ \override TextSpanner #'(bound-details right padding) = #0.6
+
+ \override TextSpanner #'(bound-details right stencil-align-dir-y) = #CENTER
+ \override TextSpanner #'(bound-details left stencil-align-dir-y) = #CENTER