diff --git a/sdm/src/java/iterator/ITicketIterator.java b/sdm/src/java/iterator/ITicketIterator.java
index af2fafa..3a88f62 100644
--- a/sdm/src/java/iterator/ITicketIterator.java
+++ b/sdm/src/java/iterator/ITicketIterator.java
@@ -2,7 +2,7 @@
 
 import java.util.Iterator;
 
-public interface ITicketIterator extends Iterator<Integer>
+public interface ITicketIterator extends Iterator<Integer> // Is this interface really necessary? In any case you could keep it though!
 {
     boolean hasNext();
 
diff --git a/sdm/src/java/singleton/DoubleLockSingleton.java b/sdm/src/java/singleton/DoubleLockSingleton.java
index 56de077..38eb6cc 100644
--- a/sdm/src/java/singleton/DoubleLockSingleton.java
+++ b/sdm/src/java/singleton/DoubleLockSingleton.java
@@ -3,12 +3,12 @@
 import java.util.Random;
 
 public class DoubleLockSingleton {
-    int behaviour;
-    private static DoubleLockSingleton new_singleton = null;
+    int behaviour; // Private and final?
+    private static DoubleLockSingleton new_singleton = null; // NewSingleton
     private DoubleLockSingleton()
     {
-        Random rand = new Random();
-        behaviour = rand.nextInt(50);
+        Random rand = new Random(); // rand is unnecessary
+        behaviour = rand.nextInt(50); // this.behaviour
     }
     public static DoubleLockSingleton getInstance()
     {