The list adapter makes it possible to perform simple whitelist or blacklist
checks. You can configure the adapter with the list to check, or you can point
it to a URL from where the list should be fetched. Lists can be simple strings,
IP addresses, or regex patterns.
Indicates how long to keep a list before discarding it.
Typically, the TTL value should be set to noticeably longer (> 2x) than the
refresh interval to ensure continued operation in the face of transient