code: def wsgi_app(self, request):
          
  
          try:
              if request.method != 'POST':
                  abort(400)
  
              try:
                  # Python 2.7 compatibility
                  data = request.data
                  if isinstance(data, str):
                      body = json.loads(data)
                  else:
                      body = json.loads(data.decode('utf-8'))
              except ValueError:
                  abort(400)
  
              if self.validate:
                  valid_cert = util.validate_request_certificate(
                      request.headers, request.data)
  
                  valid_ts = util.validate_request_timestamp(body)
  
                  if not valid_cert or not valid_ts:
                      log.error('failed to validate request')
                      abort(403)
  
              resp_obj = self.alexa.dispatch_request(body)
              return Response(response=json.dumps(resp_obj, indent=4),
                              status=200,
                              mimetype='application/json')
  
          except HTTPException as exc:
              log.exception('Failed to handle request')
              return exc
docs: Incoming request handler.
  
          :param request: Werkzeug request object