             }
 
             attributes = UICollectionViewLayoutAttributes(forCellWithIndexPath: indexPath)
-            attributes.frame = CGRectMake(xOffset, CGFloat(yOffset), calculatedItemWidth, itemHeight)
+            attributes.frame = CGRectMake(xOffset, yOffset, calculatedItemWidth, itemHeight)
             itemAttributes.append(attributes)
 
             allItemAttributes.append(attributes)
             if isFullWidth && columnCount > 1 {
-                columnHeights[0] = Double(CGRectGetMaxY(attributes.frame))
-                columnHeights[1] = Double(CGRectGetMaxY(attributes.frame))
+                columnHeights[0] = CGRectGetMaxY(attributes.frame)
+                columnHeights[1] = CGRectGetMaxY(attributes.frame)
             }
             else {
-                columnHeights[currentColumIndex] = Double(CGRectGetMaxY(attributes.frame))
+                columnHeights[currentColumIndex] = CGRectGetMaxY(attributes.frame)
             }
         }
 


        let itemCounts = allItemAttributes.count
        var index = 0
        while(index < itemCounts){
            let rect1 = allItemAttributes[index].frame
            index = min(index + unionSize, itemCounts) - 1
            let rect2 = allItemAttributes[index].frame

            return collectionView!.delegate as? StreamCollectionViewLayoutDelegate
        }
    }
    var columnHeights = [CGFloat]()
    var sectionItemAttributes = [[UICollectionViewLayoutAttributes]]()
    var allItemAttributes = [UICollectionViewLayoutAttributes]()
    var unionRects = [CGRect]()
