A scripted Layout which can function just like a Node but
also has the ability to fit into a layout box provided via
resize. It can also be intrinsically sized allowing hosting
layouts to attempt to fit to its size by using the measure
function to report desired dimensions.See Layout Scripts.
When provided this Layout can be intrinsically sized/request
to be a specific size. This is not guaranteed as the layout
may have min/max dimensions. Resize will be called with the
granted size after being measured.
