fixes as per the review from Ross Boucher

Tests/AppKit/CPCollectionViewTest.j

@@ -0,0 +1,16 @@
+// Just doing @import <AppKit/CPCollectionView.j> failed on CPWindow not being defined somewhere.
+@import <AppKit/AppKit.j>
+
+@implementation CPCollectionViewTest : OJTestCase
+
+- (void)testItemPrototypeActuallyReturnsTheItemPrototype
+{
+    var propertiesCollectionView = [[CPCollectionView alloc] initWithFrame:CGRectMakeZero()],
+        itemPrototype = [[CPCollectionViewItem alloc] init];
+
+    [propertiesCollectionView setItemPrototype:itemPrototype];
+    
+    [self assert:[CPCollectionViewItem class] equals:[[propertiesCollectionView itemPrototype] class]];
+}
+
+@end