code: def headers_received(self, start_line, headers):
      request = httputil.HTTPServerRequest(
          connection=self.request_conn,
          server_connection=self.server_conn,
          start_line=start_line,
          headers=headers,
      )
  
      self.delegate = self.router.find_handler(request)
      return self.delegate.headers_received(start_line, headers)
  
imports: from __future__ import absolute_import, division, print_function
  import re
  from functools import partial
  from tornado import httputil
  from tornado.httpserver import _CallableAdapter
  from tornado.escape import url_escape, url_unescape, utf8
  from tornado.log import app_log
  from tornado.util import basestring_type, import_object, re_unescape, unicode_type
label_desc: Use image node_id 2 for calling the _RoutingDelegate obj's underlying member method code with example usage: obj.headers_received(start_line, headers) and returns: self