code: async def body(self):
          
          if not isinstance(self._body, bytes):
              self._body = await self._body
          return self._body
docs: A helper function which blocks until the body has been read
          completely.
          Returns the bytes of the body which the user should decode.
  
          If the request does not have a body part (i.e. it is a GET
          request) this function returns None.