(footnote-text . ,(grob::calc-property-by-copy 'footnote-text))
(stencil . ,ly:balloon-interface::print)
(text . ,(grob::calc-property-by-copy 'text))
+ (X-extent . #f)
(Y-extent . #f)
(X-offset . ,(grob::calc-property-by-copy 'X-offset))
(Y-offset . ,(grob::calc-property-by-copy 'Y-offset))
(spanner-placement . ,LEFT)
(stencil . ,ly:balloon-interface::print-spanner)
(text . ,(grob::calc-property-by-copy 'text))
+ (X-extent . #f)
(Y-extent . #f)
(X-offset . ,(grob::calc-property-by-copy 'X-offset))
(Y-offset . ,(grob::calc-property-by-copy 'Y-offset))