diff --git a/extension-objects/pom.xml b/extension-objects/pom.xml
index afdf010a2..77f6ccfa2 100644
--- a/extension-objects/pom.xml
+++ b/extension-objects/pom.xml
@@ -10,6 +10,12 @@
     <modelVersion>4.0.0</modelVersion>
 
     <artifactId>extension-objects</artifactId>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+        </dependency>
+    </dependencies>
 
 
-</project>
\ No newline at end of file
+</project>
diff --git a/extension-objects/src/main/java/App.java b/extension-objects/src/main/java/App.java
index 9aa934580..af76682b8 100644
--- a/extension-objects/src/main/java/App.java
+++ b/extension-objects/src/main/java/App.java
@@ -38,6 +38,7 @@ public class App {
     SergeantExtension sergeantExtension = (SergeantExtension) unit.getUnitExtension("SergeantExtension");
     CommanderExtension commanderExtension = (CommanderExtension) unit.getUnitExtension("CommanderExtension");
 
+    //if unit have extension call the method
     if (soldierExtension != null) {
       soldierExtension.soldierReady();
     } else {
@@ -51,7 +52,7 @@ public class App {
     }
 
     if (commanderExtension != null) {
-      // commanderExtension.sergeantReady();
+      commanderExtension.commanderReady();
     } else {
       System.out.println(unit.getName() + " without CommanderExtension");
     }
diff --git a/extension-objects/src/main/java/abstractextensions/CommanderExtension.java b/extension-objects/src/main/java/abstractextensions/CommanderExtension.java
index aa716a3ae..3088c9f86 100644
--- a/extension-objects/src/main/java/abstractextensions/CommanderExtension.java
+++ b/extension-objects/src/main/java/abstractextensions/CommanderExtension.java
@@ -4,4 +4,6 @@ package abstractextensions;
  * Created by Srdjan on 27-Apr-17.
  */
 public interface CommanderExtension extends UnitExtension {
+
+  void commanderReady();
 }
diff --git a/extension-objects/src/main/java/concreteextensions/Commander.java b/extension-objects/src/main/java/concreteextensions/Commander.java
index 3de4d124a..3ce183afb 100644
--- a/extension-objects/src/main/java/concreteextensions/Commander.java
+++ b/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!");
+  }
 }
diff --git a/extension-objects/src/main/java/concreteextensions/Sergeant.java b/extension-objects/src/main/java/concreteextensions/Sergeant.java
index b2d4485c3..499ea4f63 100644
--- a/extension-objects/src/main/java/concreteextensions/Sergeant.java
+++ b/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! ");
   }
 }
diff --git a/extension-objects/src/main/java/concreteextensions/Soldier.java b/extension-objects/src/main/java/concreteextensions/Soldier.java
index e2d11e244..844abd57a 100644
--- a/extension-objects/src/main/java/concreteextensions/Soldier.java
+++ b/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!");
   }
 }
diff --git a/extension-objects/src/test/java/AppTest.java b/extension-objects/src/test/java/AppTest.java
new file mode 100644
index 000000000..88ba70da9
--- /dev/null
+++ b/extension-objects/src/test/java/AppTest.java
@@ -0,0 +1,16 @@
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class AppTest {
+  @Test
+  public void main() throws Exception {
+
+    String[] args = {};
+    App.main(args);
+  }
+
+}
\ No newline at end of file
diff --git a/extension-objects/src/test/java/concreteextensions/CommanderTest.java b/extension-objects/src/test/java/concreteextensions/CommanderTest.java
new file mode 100644
index 000000000..a5ac7b506
--- /dev/null
+++ b/extension-objects/src/test/java/concreteextensions/CommanderTest.java
@@ -0,0 +1,19 @@
+package concreteextensions;
+
+import org.junit.Test;
+import units.CommanderUnit;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class CommanderTest {
+  @Test
+  public void commanderReady() throws Exception {
+    final Commander commander = new Commander(new CommanderUnit("CommanderUnitTest"));
+
+    commander.commanderReady();
+  }
+
+}
\ No newline at end of file
diff --git a/extension-objects/src/test/java/concreteextensions/SergeantTest.java b/extension-objects/src/test/java/concreteextensions/SergeantTest.java
new file mode 100644
index 000000000..163d5c1fc
--- /dev/null
+++ b/extension-objects/src/test/java/concreteextensions/SergeantTest.java
@@ -0,0 +1,19 @@
+package concreteextensions;
+
+import org.junit.Test;
+import units.SergeantUnit;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class SergeantTest {
+  @Test
+  public void sergeantReady() throws Exception {
+    final Sergeant sergeant = new Sergeant(new SergeantUnit("SergeantUnitTest"));
+
+    sergeant.sergeantReady();
+  }
+
+}
\ No newline at end of file
diff --git a/extension-objects/src/test/java/concreteextensions/SoldierTest.java b/extension-objects/src/test/java/concreteextensions/SoldierTest.java
new file mode 100644
index 000000000..dde222d61
--- /dev/null
+++ b/extension-objects/src/test/java/concreteextensions/SoldierTest.java
@@ -0,0 +1,19 @@
+package concreteextensions;
+
+import org.junit.Test;
+import units.SoldierUnit;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class SoldierTest {
+  @Test
+  public void soldierReady() throws Exception {
+    final Soldier soldier = new Soldier(new SoldierUnit("SoldierUnitTest"));
+
+    soldier.soldierReady();
+  }
+
+}
\ No newline at end of file
diff --git a/extension-objects/src/test/java/units/CommanderUnitTest.java b/extension-objects/src/test/java/units/CommanderUnitTest.java
new file mode 100644
index 000000000..1ec498d91
--- /dev/null
+++ b/extension-objects/src/test/java/units/CommanderUnitTest.java
@@ -0,0 +1,22 @@
+package units;
+
+import abstractextensions.CommanderExtension;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class CommanderUnitTest {
+  @Test
+  public void getUnitExtension() throws Exception {
+
+    final Unit unit = new CommanderUnit("CommanderUnitName");
+
+    assertNull(unit.getUnitExtension("SoldierExtension"));
+    assertNull(unit.getUnitExtension("SergeantExtension"));
+    assertNotNull((CommanderExtension)unit.getUnitExtension("CommanderExtension"));
+  }
+
+}
\ No newline at end of file
diff --git a/extension-objects/src/test/java/units/SergeantUnitTest.java b/extension-objects/src/test/java/units/SergeantUnitTest.java
new file mode 100644
index 000000000..8fe62298c
--- /dev/null
+++ b/extension-objects/src/test/java/units/SergeantUnitTest.java
@@ -0,0 +1,22 @@
+package units;
+
+import abstractextensions.SergeantExtension;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class SergeantUnitTest {
+  @Test
+  public void getUnitExtension() throws Exception {
+
+    final Unit unit = new SergeantUnit("SergeantUnitName");
+
+    assertNull(unit.getUnitExtension("SoldierExtension"));
+    assertNotNull((SergeantExtension)unit.getUnitExtension("SergeantExtension"));
+    assertNull(unit.getUnitExtension("CommanderExtension"));
+  }
+
+}
\ No newline at end of file
diff --git a/extension-objects/src/test/java/units/SoldierUnitTest.java b/extension-objects/src/test/java/units/SoldierUnitTest.java
new file mode 100644
index 000000000..8d1fe5667
--- /dev/null
+++ b/extension-objects/src/test/java/units/SoldierUnitTest.java
@@ -0,0 +1,24 @@
+package units;
+
+import abstractextensions.SoldierExtension;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class SoldierUnitTest {
+  @Test
+  public void getUnitExtension() throws Exception {
+
+    final Unit unit = new SoldierUnit("SoldierUnitName");
+
+    assertNotNull((SoldierExtension)unit.getUnitExtension("SoldierExtension"));
+    assertNull(unit.getUnitExtension("SergeantExtension"));
+    assertNull(unit.getUnitExtension("CommanderExtension"));
+
+
+  }
+
+}
\ No newline at end of file
diff --git a/extension-objects/src/test/java/units/UnitTest.java b/extension-objects/src/test/java/units/UnitTest.java
new file mode 100644
index 000000000..08fd10d8e
--- /dev/null
+++ b/extension-objects/src/test/java/units/UnitTest.java
@@ -0,0 +1,33 @@
+package units;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by Srdjan on 03-May-17.
+ */
+public class UnitTest {
+
+  private Unit unit;
+
+  @Test
+  public void testConstGetSet() throws Exception {
+    final String name = "testName";
+    final Unit unit = new Unit(name);
+    assertEquals(name,unit.getName());
+
+    final String newName = "newName";
+    unit.setName(newName);
+    assertEquals(newName,unit.getName());
+
+
+    assertNull(unit.getUnitExtension(""));
+    assertNull(unit.getUnitExtension("SoldierExtension"));
+    assertNull(unit.getUnitExtension("SergeantExtension"));
+    assertNull(unit.getUnitExtension("CommanderExtension"));
+  }
+
+}
\ No newline at end of file