net/http/cookiejar: added simple example test

Partially fixes golang#16360

Change-Id: I01563031a1c105e54499134eed4789f6219f41ec

Author: dhaivat

src/net/http/cookiejar/example_test.go

@@ -0,0 +1,48 @@
+// Copyright 2013 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.
+
+package cookiejar_test
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"net/http/cookiejar"
+	"net/http/httptest"
+)
+
+func ExampleNew() {
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		http.SetCookie(w, &http.Cookie{Name: "COOKIE", Value: "NOM NOM NOM"})
+	}))
+	defer ts.Close()
+
+	// A nil value is valid and may be useful for testing but it is not
+	// secure: it means that the HTTP server for foo.co.uk can set a cookie
+	// for bar.co.uk.
+	//
+	// Actual implementation in package golang.org/x/net/publicsuffix
+	// jar, err := cookiejar.New(&cookiejar.Options{PublicSuffixList: publicsuffix.List})
+	jar, err := cookiejar.New(nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	client := http.Client{
+		Jar: jar,
+	}
+
+	req, err := http.NewRequest("GET", ts.URL, nil)
+	if _, err = client.Do(req); err != nil {
+		log.Fatal(err)
+	}
+
+	for _, cookie := range jar.Cookies(req.URL) {
+		fmt.Printf("%s:%s", cookie.Name, cookie.Value)
+	}
+
+	// Output:
+	// COOKIE:NOM NOM NOM
+}