bodyShape function
A body shape; each entry is (text, bullet level).
Implementation
String bodyShape(List<(String, int)> paragraphs) =>
'<p:sp><p:nvSpPr><p:cNvPr id="3" name="Body"/><p:cNvSpPr/><p:nvPr/></p:nvSpPr>'
'<p:txBody>${[for (final (text, level) in paragraphs) '<a:p><a:pPr lvl="$level"/><a:r><a:t>$text</a:t></a:r></a:p>'].join()}</p:txBody></p:sp>';