~jaro/balkon

ref: 4415c30c05dab911c592dfcbcfed8d3b46b8d87c balkon/src/Data/Text/ParagraphLayout/Internal/WithSpan.hs -rw-r--r-- 1.2 KiB 
Allow extracting ResolvedBox from WithSpan.

Separate WithSpan for sharing with other modules.