code: def fill_document(self):
          
          with self.create(Section('A section')):
              self.append('Some regular text and some ')
              self.append(italic('italic text. '))
  
              with self.create(Subsection('A subsection')):
                  self.append('Also some crazy characters: $&#{}')
docs: Add a section, a subsection and some text to the document.