diff --git a/querydsl-core/src/main/java/com/mysema/query/support/Group.java b/querydsl-core/src/main/java/com/mysema/query/support/Group.java
index 7388cb095..ee55a7476 100644
--- a/querydsl-core/src/main/java/com/mysema/query/support/Group.java
+++ b/querydsl-core/src/main/java/com/mysema/query/support/Group.java
@@ -71,6 +71,10 @@ public interface Group {
      */
     Tuple getRow(int i);
     
+    /**
+     *
+     * @return
+     */
     int size();
     
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/support/GroupBy.java b/querydsl-core/src/main/java/com/mysema/query/support/GroupBy.java
index f77244080..efeeb0d75 100644
--- a/querydsl-core/src/main/java/com/mysema/query/support/GroupBy.java
+++ b/querydsl-core/src/main/java/com/mysema/query/support/GroupBy.java
@@ -35,9 +35,7 @@ public class GroupBy implements ResultTransformer<Collection<Group>> {
     public GroupBy(Expression<?> groupBy, Expression<?>... args) {
         expressions = new Expression<?>[args.length + 1];
         expressions[0] = groupBy;
-        for (int i=0; i < args.length; i++) {
-            expressions[i+1] = args[i];
-        }
+        System.arraycopy(args, 0, expressions, 1, args.length);        
     }
 
     @Override
@@ -50,9 +48,9 @@ public class GroupBy implements ResultTransformer<Collection<Group>> {
                 Object[] row = iter.next();
                 Object groupBy = row[0];
                 // groups.values() should return Collection<GTuple> instead of Collection<? extends GTuple>
-                GTupleImpl group = (GTupleImpl) groups.get(groupBy);
+                GroupImpl group = (GroupImpl) groups.get(groupBy);
                 if (group == null) {
-                    group = new GTupleImpl();
+                    group = new GroupImpl();
                     groups.put(groupBy, group);
                 }
                 group.add(row);
@@ -73,7 +71,7 @@ public class GroupBy implements ResultTransformer<Collection<Group>> {
     }
     
     @SuppressWarnings("unchecked")
-    private class GTupleImpl implements Group {
+    private class GroupImpl implements Group {
         
         private final List<Object[]> values = new ArrayList<Object[]>();
 
diff --git a/querydsl-core/src/test/java/com/mysema/query/support/GroupByTest.java b/querydsl-core/src/test/java/com/mysema/query/support/GroupByTest.java
index bda747239..42bf32c45 100644
--- a/querydsl-core/src/test/java/com/mysema/query/support/GroupByTest.java
+++ b/querydsl-core/src/test/java/com/mysema/query/support/GroupByTest.java
@@ -27,11 +27,11 @@ import com.mysema.query.types.path.StringPath;
 
 public class GroupByTest {
 
-    private final NumberExpression<Integer> postId = new NumberPath<Integer>(Integer.class, null, "postId");
+    private final NumberExpression<Integer> postId = new NumberPath<Integer>(Integer.class, "postId");
 
-    private final StringExpression postName = new StringPath(null, "postName");
+    private final StringExpression postName = new StringPath("postName");
 
-    private final NumberExpression<Integer> commentId = new NumberPath<Integer>(Integer.class, null, "commentId");
+    private final NumberExpression<Integer> commentId = new NumberPath<Integer>(Integer.class, "commentId");
 
     static class PostWithComments {
         public Integer id;
@@ -191,7 +191,9 @@ public class GroupByTest {
         return row;
     }
     
-    private static CloseableIterator<Object[]> iterator(Object[]... rows) {
-        return new IteratorAdapter<Object[]>(Arrays.asList(rows).iterator());
+
+    @SuppressWarnings("unchecked")
+    private static <T> CloseableIterator<T> iterator(Object[]... rows) {
+        return new IteratorAdapter(Arrays.asList(rows).iterator());
     }
 }