# File lib/cheat/site.rb, line 175
    def get(title, old_version, new_version = nil)
      redirect "#{URL}/b/" and return unless old_version.to_i.nonzero?

      @sheet = Sheet.detect { |s| s.title == title }
      @old_sheet = @sheet.find_version(old_version)
      @new_sheet = (new_version ? @sheet.find_version(new_version) : @sheet)

      @diffed = Diffr.diff(@old_sheet, @new_sheet) rescue nil

      respond_to do |wants|
        wants.html { render :diff }
        wants.yaml { { @sheet.title => @diffed }.to_yaml }
      end
    end