code: func (s *poolStats) init(sum, weight float64) {
  	s.sum = sum
  	s.weight = weight
  	var avg float64
  	if weight > 0 {
  		avg = s.sum / weight
  	}
  	s.avg = avg
  	s.recent = avg
  	s.lastRecalc = mclock.Now()
  }
docs: // init initializes stats with a long term sum/update count pair retrieved from the database