diff --git a/gmail/snippets/src/main/java/UpdateSignature.java b/gmail/snippets/src/main/java/UpdateSignature.java
index b6ca985e..9bc29454 100644
--- a/gmail/snippets/src/main/java/UpdateSignature.java
+++ b/gmail/snippets/src/main/java/UpdateSignature.java
@@ -1,4 +1,4 @@
-// Copyright 2021 Google LLC
+// Copyright 2022 Google LLC
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -32,13 +32,19 @@ public class UpdateSignature {
     /**
      * Update the gmail signature.
      *
-     * @throws IOException
+     * @return the updated signature id
+     * @throws IOException - if service account credentials file not found.
      */
-    public static void updateGmailSignature() throws IOException {
-        // Load pre-authorized user credentials from the environment.
-        // TODO(developer) - See https://developers.google.com/identity for
-        // guides on implementing OAuth2 for your application.
-        GoogleCredentials credentials = GoogleCredentials.getApplicationDefault().createScoped(Collections.singleton(GmailScopes.GMAIL_SETTINGS_BASIC));
+    public static String updateGmailSignature() throws IOException {
+        // TODO(developer) - Replace with your email address.
+        String USER_EMAIL_ADDRESS = "gduser1@workspacesamples.dev";
+
+        /* Load pre-authorized user credentials from the environment.
+           TODO(developer) - See https://developers.google.com/identity for
+            guides on implementing OAuth2 for your application. */
+        GoogleCredentials credentials = GoogleCredentials.getApplicationDefault()
+                .createScoped(Collections.singleton(GmailScopes.GMAIL_SETTINGS_BASIC))
+                .createDelegated(USER_EMAIL_ADDRESS);
         HttpRequestInitializer requestInitializer = new HttpCredentialsAdapter(
                 credentials);
 
@@ -59,7 +65,7 @@ public static void updateGmailSignature() throws IOException {
                 }
             }
             // Updating a new signature
-            SendAs aliasSettings = new SendAs().setSignature("I heart cats.");
+            SendAs aliasSettings = new SendAs().setSignature("Automated Signature");
             SendAs result = service.users().settings().sendAs().patch(
                             "me",
                             primaryAlias.getSendAsEmail(),
@@ -67,6 +73,7 @@ public static void updateGmailSignature() throws IOException {
                     .execute();
             //Prints the updated signature
             System.out.println("Updated signature - " + result.getSignature());
+            return result.getSignature();
         } catch (GoogleJsonResponseException e) {
             // TODO(developer) - handle error appropriately
             System.err.println("Unable to update signature: " + e.getDetails());
diff --git a/gmail/snippets/src/test/java/TestUpdateSignature.java b/gmail/snippets/src/test/java/TestUpdateSignature.java
new file mode 100644
index 00000000..ea5bff3e
--- /dev/null
+++ b/gmail/snippets/src/test/java/TestUpdateSignature.java
@@ -0,0 +1,27 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+import org.junit.Test;
+import java.io.IOException;
+import static org.junit.Assert.assertEquals;
+
+public class TestUpdateSignature extends BaseTest{
+
+    @Test
+    public void testUpdateGmailSignature() throws IOException{
+        String signature = UpdateSignature.updateGmailSignature();
+        assertEquals("Automated Signature", signature);
+    }
+}
\ No newline at end of file