first version of pattern without Tests

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

@@ -0,0 +1,21 @@
+package concreteextensions;
+
+import abstractextensions.SergeantExtension;
+import units.SergeantUnit;
+
+/**
+ * Created by Srdjan on 27-Apr-17.
+ */
+public class Sergeant implements SergeantExtension {
+
+  private SergeantUnit unit;
+
+  public Sergeant(SergeantUnit sergeantUnit) {
+    this.unit = sergeantUnit;
+  }
+
+  @Override
+  public void sergeantReady() {
+    System.out.println("[Sergeant] " + unit.getName() + " do command! ");
+  }
+}