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require 'nokogiri'

original = "<!DOCTYPE html PUBLIC \"-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd\">
<html><body><br /></body></html>"
nokogiri = Nokogiri::HTML.parse(original)

output = nokogiri.to_html

puts "Expected: #{original}"
puts "Got: #{output}"