@interface UICollectionViewFlowLayoutInvalidationContext : UICollectionViewLayoutInvalidationContext { struct { unsigned char invalidateDelegateMetrics : 1; unsigned char invalidateAttributes : 1; } _flowLayoutInvalidationFlags; } @property (nonatomic) BOOL invalidateFlowLayoutDelegateMetrics; @property (nonatomic) BOOL invalidateFlowLayoutAttributes; - (id)init; @end