code: def dispatch(self, request, start_response):
      
      # Check if this matches any of our special handlers.
      dispatched_response = self.dispatch_non_api_requests(request,
                                                           start_response)
      if dispatched_response is not None:
        return dispatched_response
  
      # Call the service.
      try:
        return self.call_backend(request, start_response)
      except errors.RequestError as error:
        return self._handle_request_error(request, error, start_response)
docs: Handles dispatch to apiserver handlers.
  
      This typically ends up calling start_response and returning the entire
        body of the response.
  
      Args:
        request: An ApiRequest, the request from the user.
        start_response: A function with semantics defined in PEP-333.
  
      Returns:
        A string, the body of the response.