@Override
    public CapacityUnit getCapacityUnit() {
        return CapacityUnit.BYTES;
    }
Defines the unit used to calculate the capacity of the cache, which for all instances of this class is byte-size
based.

@return the unit to be used to calculate the capacity of this cache, which will be {@link CapacityUnit#BYTES}.
xmppserver/src/main/java/org/jivesoftware/util/cache/CaffeineCache.java