Test done

extension-objects/src/main/java/concreteextensions/Commander.java

@@ -13,4 +13,9 @@ public class Commander implements CommanderExtension {
   public Commander(CommanderUnit commanderUnit) {
     this.unit = commanderUnit;
   }
+
+  @Override
+  public void commanderReady() {
+    System.out.println("[Commander] " + unit.getName() + " is ready!");
+  }
 }

extension-objects/src/main/java/concreteextensions/Sergeant.java

@@ -16,6 +16,6 @@ public class Sergeant implements SergeantExtension {
 
   @Override
   public void sergeantReady() {
-    System.out.println("[Sergeant] " + unit.getName() + " do command! ");
+    System.out.println("[Sergeant] " + unit.getName() + " is ready! ");
   }
 }

extension-objects/src/main/java/concreteextensions/Soldier.java

@@ -16,6 +16,6 @@ public class Soldier implements SoldierExtension {
 
   @Override
   public void soldierReady() {
-    System.out.println("[Solider] " + unit.getName() + "  do command");
+    System.out.println("[Solider] " + unit.getName() + "  is ready!");
   }
 }