@class NSDictionary; @interface GKCollectionColumnLayout : GKCollectionFocusingLayout @property (retain, nonatomic) NSDictionary *itemAttributes; @property (retain, nonatomic) NSDictionary *headerAttributes; @property (retain, nonatomic) NSDictionary *decorationAttributes; @property (retain, nonatomic) NSDictionary *footerAttributes; - (struct CGSize { double x0; double x1; })collectionViewContentSize; - (void)prepareLayout; - (id)layoutAttributesForSupplementaryViewOfKind:(id)a0 atIndexPath:(id)a1; - (id)layoutAttributesForElementsInRect:(struct CGRect { struct CGPoint { double x0; double x1; } x0; struct CGSize { double x0; double x1; } x1; })a0; - (id)layoutAttributesForItemAtIndexPath:(id)a0; - (void).cxx_destruct; - (void)applyDefaults; @end