Setting static DNS entry in cache

Hello, I would like to set a static DNS entry in Firefox's cache. So far I've been unable to figure out if this is possible as most everything points to extending the cache time and entry list size. I've located the following variables but am wondering if I haven't scowered the internet long enough to find the magic entry. Or if there is another way / work around.

network.dnsCacheEntries
network.dnsCacheExpiration
network.dns.disablePrefetch
network.dns.disablePrefetchFromHTTPS
network.dns.disableIPv6
network.dns.ipv4OnlyDomains