diff --git a/src/test/java/eu/ztsh/training/hackerrank/HackerRankTest.java b/src/test/java/eu/ztsh/training/hackerrank/HackerRankTest.java
index 512566c..cf59987 100644
--- a/src/test/java/eu/ztsh/training/hackerrank/HackerRankTest.java
+++ b/src/test/java/eu/ztsh/training/hackerrank/HackerRankTest.java
@@ -4,14 +4,9 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.InputStream;
 import java.io.PrintStream;
-import java.lang.invoke.MethodHandles;
-import java.lang.invoke.VarHandle;
-import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Modifier;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Scanner;
 import org.junit.jupiter.api.AfterAll;
 import org.junit.jupiter.api.BeforeAll;
 
diff --git a/src/test/java/eu/ztsh/training/hackerrank/ReflectionHelper.java b/src/test/java/eu/ztsh/training/hackerrank/ReflectionHelper.java
index a32f901..498becf 100644
--- a/src/test/java/eu/ztsh/training/hackerrank/ReflectionHelper.java
+++ b/src/test/java/eu/ztsh/training/hackerrank/ReflectionHelper.java
@@ -10,6 +10,7 @@ import eu.ztsh.training.hackerrank.SolutionClassDescription.FieldModifier;
 
 public class ReflectionHelper {
 
+    // https://stackoverflow.com/a/56043252
     static {
         try {
             var lookup = MethodHandles.privateLookupIn(Field.class, MethodHandles.lookup());