code: async def send_message(  # type: ignore
          self, request: str, response_expected: bool, **kwargs: Any
      ) -> Response:
          
          headers = dict(self.DEFAULT_HEADERS)
          headers.update(kwargs.pop("headers", {}))
  
          response = await self.client.fetch(
              self.endpoint, method="POST", body=request, headers=headers, **kwargs
          )
  
          return Response(response.body.decode(), raw=response)
docs: Transport the message to the server and return the response.
  
          Args:
              request: The JSON-RPC request string.
              response_expected: Whether the request expects a response.
  
          Returns:
              A Response object.