// per bouncycastle
        // <li>1: K(i) := PRF( KI, [i]_2 || Label || 0x00 || Context || [L]_2 ) with the counter at the very beginning
        // of the fixedInputData (The default implementation has this format)</li>
        // with the parameters
        // <li>1. KDFCounterParameters(ki, null, "Label || 0x00 || Context || [L]_2]", 8);

        // all fixed inputs go into the suffix:
        // + label

  }

  public void testIteratorRemove_actualMap() {
    // Override to avoid using mocks.
    multiset = ConcurrentHashMultiset.create();

    multiset.add(KEY);
    multiset.add(KEY + "_2");
    multiset.add(KEY);

    int mutations = 0;
    for (Iterator<String> it = multiset.iterator(); it.hasNext(); ) {
      it.next();
      it.remove();
      mutations++;
    }