code: async def handle_post_request(self, environ):
          
          length = int(environ.get('CONTENT_LENGTH', '0'))
          if length > self.server.max_http_buffer_size:
              raise exceptions.ContentTooLongError()
          else:
              body = await environ['wsgi.input'].read(length)
              p = payload.Payload(encoded_payload=body)
              for pkt in p.packets:
                  await self.receive(pkt)
docs: Handle a long-polling POST request from the client.