if got != want {
		t.Errorf("got = %+v; want = %+v", got, want)
	}
}

// Issue 18327: verify we always do a deep copy of the Request.Header map
// before any mutations.
func TestClonesRequestHeaders(t *testing.T) {
	log.SetOutput(io.Discard)
	defer log.SetOutput(os.Stderr)
	req, _ := http.NewRequest("GET", "http://foo.tld/", nil)
	req.RemoteAddr = "1.2.3.4:56789"
	rp := &ReverseProxy{