restructured code, finalizing

src/ChainQueue.java

@@ -94,6 +94,31 @@ public class ChainQueue<E> implements Queue<E> {
         return false;
     }
 
+    @Override
+    public E poll() { // poll next from queue and remove the first
+        E temp = null;
+        if (!this.isEmpty()) {
+            temp = getFirst().getData();
+            setFirst(getFirst().getNext());
+        }
+        return temp;
+    }
+
+    @Override
+    public E element() {
+        return null;
+    }
+
+    @Override
+    public E peek() { // only "see" into the queue and do not remove anything
+        if (!this.isEmpty()) {
+            return getFirst().getData();
+        }
+        return null;
+    }
+
+    /*** the following is not implemented because it's not needed here ***/
+
     @Override
     public Iterator<E> iterator() {
         return null;
@@ -148,27 +173,4 @@ public class ChainQueue<E> implements Queue<E> {
     public E remove() {
         return null;
     }
-
-    @Override
-    public E poll() { // poll next from queue and remove the first
-        E temp = null;
-        if (!this.isEmpty()) {
-            temp = getFirst().getData();
-            setFirst(getFirst().getNext());
-        }
-        return temp;
-    }
-
-    @Override
-    public E element() {
-        return null;
-    }
-
-    @Override
-    public E peek() { // only "see" into the queue and do not remove anything
-        if (!this.isEmpty()) {
-           return getFirst().getData();
-        }
-        return null;
-    }
 }