def duration_human
      return nil unless duration
      seconds = duration / 1000
      if seconds >= 86_400.0 # 1 day
        "#{(seconds / 86_400).to_i}d #{Time.at(seconds).strftime('%-Hh %-Mm')}"
      elsif seconds >= 3600.0 # 1 hour
        Time.at(seconds).strftime('%-Hh %-Mm')
      elsif seconds >= 60.0 # 1 minute
        Time.at(seconds).strftime('%-Mm %-Ss')
      elsif seconds >= 1.0 # 1 second
        "#{format('%.3f', seconds)}s"
      else
        duration_to_s
      end
    end
def duration_human
      return nil unless duration
      seconds = duration / 1000
      if seconds >= 86_400.0 # 1 day
        "#{(seconds / 86_400).to_i}d #{Time.at(seconds).strftime('%-Hh %-Mm')}"
      elsif seconds >= 3600.0 # 1 hour
        Time.at(seconds).strftime('%-Hh %-Mm')
      elsif seconds >= 60.0 # 1 minute
        Time.at(seconds).strftime('%-Mm %-Ss')
      elsif seconds >= 1.0 # 1 second
        "#{format('%.3f', seconds)}s"
      else
        duration_to_s
      end
    end
Returns [String] the duration in human readable form