text: // Copyright 2018 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  // +build go1.11
  
  package http2
  
  import (
  	"net/http/httptrace"
  	"net/textproto"
  )
  
  func traceHasWroteHeaderField(trace *httptrace.ClientTrace) bool {
  	return trace != nil && trace.WroteHeaderField != nil
  }
  
  func traceWroteHeaderField(trace *httptrace.ClientTrace, k, v string) {
  	if trace != nil && trace.WroteHeaderField != nil {
  		trace.WroteHeaderField(k, []string{v})
  	}
  }
  
  func traceGot1xxResponseFunc(trace *httptrace.ClientTrace) func(int, textproto.MIMEHeader) error {
  	if trace != nil {
  		return trace.Got1xxResponse
  	}
  	return nil
  }
  