public static interface Hash.Strategy<K>
Custom hash structures (e.g., ObjectOpenCustomHashSet) allow to hash objects
using arbitrary functions, a typical example being that of arrays. Of course,
one has to compare objects for equality consistently with the chosen
function. A hash strategy, thus, specifies an equality method and a hash function, with the obvious property that
equal objects must have the same hash code.
If your custom collection must be able to contain null,
then your strategy must be able to handle null, too.
int hashCode(K o)
o - an object (or null).