class Kramdown::Converter::Html

def convert_a(el, indent, opts)
  do_obfuscation = el.options[:attr]['href'] =~ /^mailto:/
  if do_obfuscation
    el = Marshal.load(Marshal.dump(el)) # so that the original is not changed
    href = obfuscate(el.options[:attr]['href'].sub(/^mailto:/, ''))
    mailto = obfuscate('mailto')
    el.options[:attr]['href'] = "#{mailto}:#{href}"
  end
  res = inner(el, indent, opts)
  res = obfuscate(res) if do_obfuscation
  "<a#{html_attributes(el)}>#{res}</a>"
end