Signify that Request and Response from RequestCtx and Header from Request and Response mustn't be copied by value

http.go

@@ -16,6 +16,8 @@ import (
 // and use CopyTo() instead.
 type Request struct {
 	// Request header
+	//
+	// Copying Header by value is forbidden. Use pointer to Header instead.
 	Header RequestHeader
 
 	body []byte
@@ -36,6 +38,8 @@ type Request struct {
 // and use CopyTo() instead.
 type Response struct {
 	// Response header
+	//
+	// Copying Header by value is forbidden. Use pointer to Header instead.
 	Header ResponseHeader
 
 	body []byte

server.go

@@ -219,9 +219,13 @@ func TimeoutHandler(h RequestHandler, timeout time.Duration, msg string) Request
 // before return.
 type RequestCtx struct {
 	// Incoming request.
+	//
+	// Copying Request by value is forbidden. Use pointer to Request instead.
 	Request Request
 
 	// Outgoing response.
+	//
+	// Copying Response by value is forbidden. Use pointer to Response instead.
 	Response Response
 
 	id uint64