The example from this answer doesn't show the swimlanes in SVG:
http://www.plantuml.com/plantuml/svg/NOmn3e0W40HxNa6ffPJm6eH3BkfT0YGsFDxJn9ZGpknEhnVIuGcMhcp2KfjJja9WYaxrJngHBMCHXabFYNdMBGF9b4yGGvjJG17J_tc2gm-xRgnVXiA6vkYDkm40
They're not visible in Chrome's SVG rendering. I'm also using Inkscape with LyX and the swimlanes don't show up there, either.
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