The default sizes to use for section footers.
- iOS 6.0+
- Mac Catalyst 13.0+
- tvOS 9.0+
If the delegate does not implement the
collection method, the flow layout object uses the default footer sizes set for this property.
During layout, only the size that corresponds to the appropriate scrolling direction is used. For example, for the vertical scrolling direction, the layout object uses the height value specified by this property. (In that instance, the width of the footer would be set to the width of the collection view.) If the size in the appropriate scrolling dimension is 0, no footer is added.
The default size values are (0, 0).