private int hash(Object object) {
        int h = object.hashCode();
        h ^= (h >>> DOUG_LEA_BLACK_MAGIC_OPERAND_1) ^ (h >>> DOUG_LEA_BLACK_MAGIC_OPERAND_2);
        return h ^ (h >>> DOUG_LEA_BLACK_MAGIC_OPERAND_3) ^ (h >>> DOUG_LEA_BLACK_MAGIC_OPERAND_4);
    }
Returns a hash code for non-null Object x.
<p/>
This function ensures that hashCodes that differ only by constant
multiples at each bit position have a bounded number of collisions. (Doug
Lea)
stroom-util/src/main/java/stroom/util/concurrent/StripedLock.java