code: def display(self, filename=None):
          
  
          if filename is None:
              filename = self.original_filename
  
          # write to a (by default temporary) file
          with open(filename, 'w') as output_svg:
              output_svg.write(etree.tostring(self.tree.getroot()))
  
          open_in_browser(filename)
docs: Displays/opens the doc using the OS's default application.