def eta
      if @current == 0
        "ETA:  --:--:--"
      else
        elapsed_time = Time.now - @start_time
        estimated_time = elapsed_time * @total / @current - elapsed_time
        sprintf("ETA:  %s", format_time(estimated_time))
      end
    end
def eta
      if @current == 0
        "ETA:  --:--:--"
      else
        elapsed_time = Time.now - @start_time
        estimated_time = elapsed_time * @total / @current - elapsed_time
        sprintf("ETA:  %s", format_time(estimated_time))
      end
    end
ETA stands for Estimated Time of Arrival.