diff --git a/.gitignore b/.gitignore
index 3736e95..cf5943b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,23 @@
-target
-.settings
-.project
-.classpath
-.iml
+.DS_Store
+*.iml
+*.ipr
+*.iws
+*.orig
+*.rej
+**/.keep
+*.sdf
+*.suo
+*.vcxproj.user
+.dev-tools/
+.hugo_build.lock
 .idea
+.classpath
 .mvn/.develocity/
-*.versionsBackup
+.project
+.settings
+target
+build
+patchprocess
+dependency-reduced-pom.xml
+.mvn/wrapper/maven-wrapper.jar
+.vscode/
diff --git a/test/src/test/java/org/apache/ratis/thirdparty/com/google/protobuf/ProtobufTest.java b/test/src/test/java/org/apache/ratis/thirdparty/com/google/protobuf/ProtobufTest.java
new file mode 100644
index 0000000..1aaf1c6
--- /dev/null
+++ b/test/src/test/java/org/apache/ratis/thirdparty/com/google/protobuf/ProtobufTest.java
@@ -0,0 +1,33 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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
+ *
+ *     http://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.
+ */
+package org.apache.ratis.thirdparty.com.google.protobuf;
+
+import java.nio.ByteBuffer;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+/** Unit test for protobuf in order to access package private artifacts. */
+public class ProtobufTest {
+  @Test
+  public void testNioByteStringExist() {
+    final byte[] array = new byte[10];
+    final NioByteString nioByteString = new NioByteString(ByteBuffer.wrap(array));
+    assertEquals(array.length, nioByteString.size());
+  }
+}