Log
A tagging interface to mark implementations that are suitable for use as a key for looking up per log site persistent state. Normally the class used is just LogSite but other, more specific, keys can be used. There are no method requirements on this interface, but the instance must have correct equals(), hashCode() and toString() implementations and must be at least as unique as the associated LogSite (i.e. two keys created for different log sites must never be equal).