code: def send_exception(self, code, exc_info=None, headers=None):
          "send an error response including a backtrace to the client"
          if headers is None:
              headers = {}
  
          if not exc_info:
              exc_info = sys.exc_info()
  
          self.send_error_msg(code,
                              traceback.format_exception(*exc_info),
                              headersf send_exception(self, code, exc_info=None, headers=None):
          "send an error response including a backtrace to the client"
          if headers is None:
              headers = {}
  
          if not exc_info:
              exc_info = sys.exc_info()
  
          self.send_error_msg(code,
                              traceback.format_exception(*exc_info),
                              headers)
docs: send an error response including a backtrace to the client