def fill_placeholders (out)
      re = Regexp.new('%' + @replacement_hash + '%(\d+)%')
      out.gsub re do |m|
        m.gsub!(re, "\\1")
        @placeholders[m.to_i]
      end
    end
def fill_placeholders (out)
      re = Regexp.new('%' + @replacement_hash + '%(\d+)%')
      out.gsub re do |m|
        m.gsub!(re, "\\1")
        @placeholders[m.to_i]
      end
    end
fill placeholders