host.go
func (h Host) Rescan() (scan Scan) {
	return Init().
		AddPorts(h.parentScan.configPorts...).
		AddTCPPorts(h.parentScan.configTCPPorts...).
		AddUDPPorts(h.parentScan.configUDPPorts...).
		AddHosts(h.Address).
		AddFlags(h.parentScan.configOpts...)
}
func (h Host) Rescan() (scan Scan) {
	return Init().
		AddPorts(h.parentScan.configPorts...).
		AddTCPPorts(h.parentScan.configTCPPorts...).
		AddUDPPorts(h.parentScan.configUDPPorts...).
		AddHosts(h.Address).
		AddFlags(h.parentScan.configOpts...)
}
// Rescan the target. Normally used for finding differences between scans
// at two points in time.