disabling lease cache using cache cache-threshold value

According to ARM (section 8.2.29. Lease Caching) setting cache-threshold to 0. or less, or 1. or more will disable feature

if the cache-threshold is configured and is between 0. and 1. it expresses the percentage of the lease valid lifetime which is allowed for the lease age. Values below and including 0. and values greater than 1. disable the lease cache feature.

But instead Kea returns configuration error in both cases:

ERROR [kea-dhcp6.dhcp6/20974.139963599241728] DHCP6_CONFIG_LOAD_FAIL configuration error using file: /home/wlodek/installed/git/etc/kea/kea-dhcp6.conf, reason: subnet configuration failed: cache-threshold: 1 is invalid, it must be greater than 0.0 and less than 1.0
ERROR [kea-dhcp6.dhcp6/20974.139963599241728] DHCP6_INIT_FAIL failed to initialize Kea server: configuration error using file '/home/wlodek/installed/git/etc/kea/kea-dhcp6.conf': subnet configuration failed: cache-threshold: 1 is invalid, it must be greater than 0.0 and less than 1.0

ERROR [kea-dhcp6.dhcp6/27470.139959572206080] DHCP6_CONFIG_LOAD_FAIL configuration error using file: /home/wlodek/installed/git/etc/kea/kea-dhcp6.conf, reason: subnet configuration failed: cache-threshold: 0 is invalid, it must be greater than 0.0 and less than 1.0
ERROR [kea-dhcp6.dhcp6/27470.139959572206080] DHCP6_INIT_FAIL failed to initialize Kea server: configuration error using file '/home/wlodek/installed/git/etc/kea/kea-dhcp6.conf': subnet configuration failed: cache-threshold: 0 is invalid, it must be greater than 0.0 and less than 1.0

Two solutions:

• changing doc
• changing code While making this decision please keep in mind that there is second parameter "cache-max-age" and when this is set to 0 feature is actually disabled