anchor.diff:      (assertValueOneOf "ForceDHCPv6PDOtherInformation" boolValues)
     ];
   
  +  checkIpv6PrefixDelegation = checkUnitConfig "IPv6PrefixDelegation" [
  +    (assertOnlyFields [
  +      "Managed"  "OtherInformation"  "RouterLifetimeSec"
  +      "RouterPreference"  "EmitDNS"  "DNS"  "EmitDomains"  "Domains"
  +      "DNSLifetimeSec"
  +    ])
  +    (assertValueOneOf "Managed" boolValues)
  +    (assertValueOneOf "OtherInformation" boolValues)
  +    (assertValueOneOf "RouterPreference" ["high" "medium" "low" "normal" "default"])
  +    (assertValueOneOf "EmitDNS" boolValues)
  +    (assertValueOneOf "EmitDomains" boolValues)
  +    (assertMinimum "DNSLifetimeSec" 0)
  +  ];
  +
     checkDhcpServer = checkUnitConfig "DHCPServer" [
       (assertOnlyFields [
         "PoolOffset" "PoolSize" "DefaultLeaseTimeSec" "MaxLeaseTimeSec"
  
positive.code:             ${attrsToSection def.dhcpV6Config}
  
            ''}
            ${optionalString (def.dhcpServerConfig != { }) ''
              [DHCPServer]
              ${attrsToSection def.dhcpServerConfig}
  
negative.code:       description = ''
          Each attribute in this set specifies an option in the
          <literal>[DHCPv6]</literal> section of the unit.  See
          <citerefentry><refentrytitle>systemd.network</refentrytitle>
          <manvolnum>5</manvolnum></citerefentry> for details.
        '';
      };
  
      ipv6PrefixDelegationConfig = mkOption {
        default = {};
        example = { EmitDNS = true; Managed = true; OtherInformation = true; };
        type = types.addCheck (types.attrsOf unitOption) checkIpv6PrefixDelegation;
        description = ''
          Each attribute in this set specifies an option in the
          <literal>[IPv6PrefixDelegation]</literal> section of the unit.  See
          <citerefentry><refentrytitle>systemd.network</refentrytitle>
          <manvolnum>5</manvolnum></citerefentry> for details.
        '';
  