public void setIterations(int iterations) {
        this.iterations = Math.max(DEFAULT_ITERATIONS, iterations);
    }
Sets the iterations used to previously compute AN ALREADY GENERATED HASH.
<p/>
This is provided <em>ONLY</em> to reconstitute an already-created Hash instance.  It should ONLY ever be
invoked when re-constructing a hash instance from an already-hashed value.

@param iterations the number of hash iterations used to previously create the hash/digest.
@since 1.2
crypto/hash/src/main/java/org/apache/shiro/crypto/hash/SimpleHash.java