# File lib/travis/tools/formatter.rb, line 10
      def duration(seconds, suffix = nil)
        return "none" if seconds.nil?
        seconds          = (Time.now - seconds).to_i if seconds.is_a? Time
        output           = []
        minutes, seconds = seconds.divmod(60)
        hours, minutes   = minutes.divmod(60)
        output << "#{hours  } hrs" if hours > 0
        output << "#{minutes} min" if minutes > 0
        output << "#{seconds} sec" if seconds > 0 or output.empty?
        output << suffix           if suffix
        output.join(" ")
      end