code: def _serve_file(self, abspath, params):
      
      relpath = os.path.relpath(abspath, self._root)
      breadcrumbs = self._create_breadcrumbs(relpath)
      link_path = urlunparse(['', '', relpath, '', urlencode(params), ''])
      args = self._default_template_args('file.html')
      args.update({'root_parent': os.path.dirname(self._root),
                   'breadcrumbs': breadcrumbs,
                   'link_path': link_path})
      content = self._renderer.render_name('base.html', args).encode("utf-8")
      self._send_content(content, 'text/html')
docs: Show a file.
  
      The actual content of the file is rendered by _handle_content.