You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: content_helper.rb
    path of file: ./repos/linuxfr.org/app/helpers
    
    the code of the file until where you have to start completion: # encoding: utf-8
module ContentHelper

  def spellcheck(html)
    html = h html unless html.htm
    
  def htmldiff(was, new)
    dmp = DiffPatchMatch.new
    diffs = dmp.diff_main(was || "", new)
    dmp.diff_cleanupSemantic diffs
    diffs.map do |diff|
      case diff.op
      when :equal   then h diff.text
      when :delete  then %Q{<del class="diff">#{h diff.text}</del>}
      when :insert  then %Q{<ins class="diff">#{h diff.text}</ins>}
      end
    end.join.html_safe
  end