code: func (h *HCI) Scan(allowDup bool) error {
  	h.params.scanEnable.FilterDuplicates = 1
  	if allowDup {
  		h.params.scanEnable.FilterDuplicates = 0
  	}
  	h.params.scanEnable.LEScanEnable = 1
  	h.adHist = make([]*Advertisement, 128)
  	h.adLast = 0
  	return h.Send(&h.params.scanEnable, nil)
  }
docs: // Scan starts scanning.