code: func NewWindowed(n int, minValue, maxValue int64, sigfigs int) *WindowedHistogram {
  	w := WindowedHistogram{
  		idx: -1,
  		h:   make([]Histogram, n),
  		m:   New(minValue, maxValue, sigfigs),
  	}
  
  	for i := range w.h {
  		w.h[i] = *New(minValue, maxValue, sigfigs)
  	}
  	w.Rotate()
  
  	return &w
  }
docs: // NewWindowed creates a new WindowedHistogram with N underlying histograms with
  // the given parameters.