code: func ValidateIPNetFromString(subnet string, minAddrs int64, fldPath *field.Path) field.ErrorList {
  	allErrs := field.ErrorList{}
  	_, svcSubnet, err := net.ParseCIDR(subnet)
  	if err != nil {
  		allErrs = append(allErrs, field.Invalid(fldPath, subnet, "couldn't parse subnet"))
  		return allErrs
  	}
  	numAddresses := ipallocator.RangeSize(svcSubnet)
  	if numAddresses < minAddrs {
  		allErrs = append(allErrs, field.Invalid(fldPath, subnet, "subnet is too small"))
  	}
  	return allErrs
  }
docs: // ValidateIPNetFromString validates network portion of ip address