Adds sendEach snippets for FCM.

snippets/messaging.go

@@ -236,7 +236,7 @@
 	// [END send_multicast_error]
 }
 
 func sendEachForMulticastAndHandleErrors(ctx context.Context, client *messaging.Client) {
 	// [START send_each_for_multicast_error]
 	// Create a list containing up to 500 registration tokens.
 	// This registration tokens come from the client FCM SDKs.
@@ -272,6 +272,42 @@
 	// [END send_each_for_multicast_error]
 }
 
+func sendEachForMulticastAndHandleErrors(ctx context.Context, client *messaging.Client) {
+	// [START send_each_for_multicast_error]
+	// Create a list containing up to 500 registration tokens.
+	// This registration tokens come from the client FCM SDKs.
+	registrationTokens := []string{
+		"YOUR_REGISTRATION_TOKEN_1",
+		// ...
+		"YOUR_REGISTRATION_TOKEN_n",
+	}
+	message := &messaging.MulticastMessage{
+		Data: map[string]string{
+			"score": "850",
+			"time":  "2:45",
+		},
+		Tokens: registrationTokens,
+	}
+
+	br, err := client.SendEachForMulticast(context.Background(), message)
+	if err != nil {
+		log.Fatalln(err)
+	}
+
+	if br.FailureCount > 0 {
+		var failedTokens []string
+		for idx, resp := range br.Responses {
+			if !resp.Success {
+				// The order of responses corresponds to the order of the registration tokens.
+				failedTokens = append(failedTokens, registrationTokens[idx])
+			}
+		}
+
+		fmt.Printf("List of tokens that caused failures: %v\n", failedTokens)
+	}
+	// [END send_each_for_multicast_error]
+}
+
 func sendDryRun(ctx context.Context, client *messaging.Client) {
 	message := &messaging.Message{
 		Data: map[string]string{