     }
 }
 
+// MARK: - KVO check for `sectionHeadersPinToVisibleBounds`
 extension AKPFlowLayout {
      /// KVO check for `sectionHeadersPinToVisibleBounds`.
      /// For iOS9, needs to ensure the impl does not interfere with `sectionHeadersPinToVisibleBounds`

                    sectionHeadersLayoutAttributes.stretchFactor = fabs(offset)
                    previousStretchFactor = sectionHeadersLayoutAttributes.stretchFactor
                } else {
                    // here we need to limit the stretch
                    sectionFrame.size.height = firsSectionMaximumStretchHeight
                    sectionHeadersLayoutAttributes.stretchFactor = previousStretchFactor
                }

                layoutAttributes.append(attributes)
            }
        }
        // for section headers, need to adjust their attributes
        for attributes in layoutAttributes where
            attributes.representedElementKind == UICollectionElementKindSectionHeader {
                (attributes.frame, attributes.zIndex) = adjustLayoutAttributes(forSectionAttributes: attributes)
