code: def handle_error(self, type_, value, tb):
          
          if not issubclass(type_, pywsgi.GreenletExit):
              self.server.loop.handle_error(self.environ, type_, value, tb)
          if self.response_length:
              self.close_connection = True
          else:
              tb_stream = traceback.format_exception(type_, value, tb)
              del tb
              tb_stream.append('\n')
              tb_stream.append(pprint.pformat(self.environ))
              body = ''.join(tb_stream)
              headers = pywsgi._INTERNAL_ERROR_HEADERS[:]
              headers[2] = ('Content-Length', str(len(body)))
  
              self.start_response(pywsgi._INTERNAL_ERROR_STATUS, headers)
              self.write(body)
docs: This method copies the code from pywsgi.WSGIHandler.handle_error,
          change the write part to be a reflection of traceback and environ