1# pick-first-value data expression 2 3# empty configs are not accepted by Kea 4default-lease-time 1800; 5 6# reduce literals 7class "literal" { 8 match if option dhcp6.client-data = 9 pick-first-value(substring("abcd",0,0),null,"foobar"); 10} 11 12# null 13class "null" { 14 match if option dhcp6.client-data = pick(null); 15} 16