code: def visit_snippet(self, node):
      
      lang = self.highlightlang
      linenos = node.rawsource.count('\n') >= self.highlightlinenothreshold - 1
      fname = node['filename']
      highlight_args = node.get('highlight_args', {})
      if 'language' in node:
          # code-block directives
          lang = node['language']
          highlight_args['force'] = True
      if 'linenos' in node:
          linenos = node['linenos']
  
      def warner(msg):
          self.builder.warn(msg, (self.builder.current_docname, node.line))
  
      highlighted = self.highlighter.highlight_block(node.rawsource, lang,
                                                     warn=warner,
                                                     linenos=linenos,
                                                     **highlight_args)
      starttag = self.starttag(node, 'div', suffix='',
                               CLASS='highlight-%s snippet' % lang)
      self.body.append(starttag)
      self.body.append('<div class="snippet-filename">%s</div>\n''' % (fname,))
      self.body.append(highlighted)
      self.body.append('</div>\n')
      raise nodes.SkipNode
docs: HTML document generator visit handler