code: def add_link(self, **kwgs):
          
          self.links.append(kwgs)
          if kwgs.get('type') == 'text/javascript':
              if 'scripted' not in self.properties:
                  self.properties.append('scripted')
docs: Add additional link to the document. Links will be embeded only inside of this document.
  
          >>> add_link(href='styles.css', rel='stylesheet', type='text/css')