diff --git a/build.gradle b/build.gradle
index ef24698..abc10ac 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,9 +17,17 @@ repositories {
 }
 
 dependencies {
+    testImplementation(platform('org.junit:junit-bom:6.1.0-M1'))
+    testImplementation('org.junit.jupiter:junit-jupiter')
+    testRuntimeOnly('org.junit.platform:junit-platform-launcher')
+
     implementation 'org.apache.commons:commons-lang3:3.20.0'
     implementation 'org.json:json:20250517'
-    implementation 'org.apache.logging.log4j:log4j-core:2.25.2'
+    implementation 'org.apache.logging.log4j:log4j-core:3.0.0-beta3'
+}
+
+test {
+    useJUnitPlatform()
 }
 
 java {
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
index 1b33c55..f8e1ee3 100644
Binary files a/gradle/wrapper/gradle-wrapper.jar and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index bad7c24..23449a2 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.2.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.2.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
diff --git a/gradlew b/gradlew
index 23d15a9..adff685 100755
--- a/gradlew
+++ b/gradlew
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 #
-# Copyright © 2015-2021 the original authors.
+# Copyright © 2015 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -114,7 +114,6 @@ case "$( uname )" in                #(
   NONSTOP* )        nonstop=true ;;
 esac
 
-CLASSPATH="\\\"\\\""
 
 
 # Determine the Java command to use to start the JVM.
@@ -172,7 +171,6 @@ fi
 # For Cygwin or MSYS, switch paths to Windows format before running java
 if "$cygwin" || "$msys" ; then
     APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
-    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
 
     JAVACMD=$( cygpath --unix "$JAVACMD" )
 
@@ -212,7 +210,6 @@ DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
-        -classpath "$CLASSPATH" \
         -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
         "$@"
 
diff --git a/gradlew.bat b/gradlew.bat
index db3a6ac..c4bdd3a 100644
--- a/gradlew.bat
+++ b/gradlew.bat
@@ -70,11 +70,10 @@ goto fail
 :execute
 @rem Setup the command line
 
-set CLASSPATH=
 
 
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
 
 :end
 @rem End local scope for the variables with windows NT shell
diff --git a/src/main/java/Main.java b/src/main/java/Main.java
index df0fbde..7bbfeb7 100644
--- a/src/main/java/Main.java
+++ b/src/main/java/Main.java
@@ -5,8 +5,11 @@ public class Main {
   public static final Logger logger = LogManager.getLogger();
 
   public static void main(String[] args) {
-    Runtime.getRuntime()
-        .addShutdownHook(new Thread(() -> logger.debug("Application is shutting down")));
-    logger.debug("Application started");
+    logger.debug("Hello");
+    logger.debug(add(2, 3));
+  }
+
+  public static int add(int a, int b) {
+    return a + b;
   }
 }
diff --git a/src/test/java/MainTest.java b/src/test/java/MainTest.java
new file mode 100644
index 0000000..d99f069
--- /dev/null
+++ b/src/test/java/MainTest.java
@@ -0,0 +1,11 @@
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+class MainTest {
+  @Test
+  void add() {
+    assertEquals(0, Main.add(-2, 2));
+    assertEquals(0, Main.add(2, -2));
+  }
+}