var fabOptionSize: FabSize
The size of each FabOption in this orientation (NOT the size of the ExpandableFab. For that, see property efabSize). Must be FabSize.MINI, FabSize.NORMAL, FabSize.AUTO or FabSize.CUSTOM. FabSize.CUSTOM should be used when you're setting the size of the FabOptions' layout_width and layout_height to a custom value manually (when using CUSTOM, make sure to also set app:fabCustomSize equal to your custom layout_width/layout_height size and app:maxImageSize equal to your icon size in order to ensure your icon is centered properly). Default value is FabSize.MINI.
Usage of this property is preferred over the inherited set/getSize methods on individual FabOptions.