code: def apply(self):
          
          source = self.document['source']
  
          self.reporter.info('AutoStructify: %s' % source)
  
          # only transform markdowns
          if not source.endswith(tuple(self.config['commonmark_suffixes'])):
              return
  
          self.url_resolver = self.config['url_resolver']
          assert callable(self.url_resolver)
  
          self.state_machine = DummyStateMachine()
          self.current_level = 0
          self.file_dir = os.path.abspath(os.path.dirname(self.document['source']))
          self.root_dir = os.path.abspath(self.document.settings.env.srcdir)
          self.traverse(self.document)
docs: Apply the transformation by configuration.