diff --git a/marker/src/main/java/App.java b/marker/src/main/java/App.java
index 8a08a8f70..0908503e5 100644
--- a/marker/src/main/java/App.java
+++ b/marker/src/main/java/App.java
@@ -46,7 +46,7 @@ public class App {
    * @param args command line args
    */
   public static void main(String[] args) {
-    final Logger logger = LoggerFactory.getLogger(App.class);
+    final var logger = LoggerFactory.getLogger(App.class);
     var guard = new Guard();
     var thief = new Thief();
 
@@ -59,7 +59,7 @@ public class App {
 
     //noinspection ConstantConditions
     if (thief instanceof Permission) {
-      thief.doNothing();
+      thief.steal();
     } else {
       thief.doNothing();
     }
diff --git a/marker/src/main/java/Guard.java b/marker/src/main/java/Guard.java
index 54443603c..9e7b731b6 100644
--- a/marker/src/main/java/Guard.java
+++ b/marker/src/main/java/Guard.java
@@ -28,7 +28,6 @@ import org.slf4j.LoggerFactory;
  * Class defining Guard.
  */
 public class Guard implements Permission {
-
   private static final Logger LOGGER = LoggerFactory.getLogger(Guard.class);
 
   protected void enter() {
diff --git a/marker/src/main/java/Thief.java b/marker/src/main/java/Thief.java
index 22155ef7b..0e4cf92e3 100644
--- a/marker/src/main/java/Thief.java
+++ b/marker/src/main/java/Thief.java
@@ -28,10 +28,9 @@ import org.slf4j.LoggerFactory;
  * Class defining Thief.
  */
 public class Thief {
-
   private static final Logger LOGGER = LoggerFactory.getLogger(Thief.class);
 
-  protected static void steal() {
+  protected void steal() {
     LOGGER.info("Steal valuable items");
   }