private StringToStringMap update(TestStep testStep, SecurityTestRunContext context)
      throws XmlException, Exception {
    StringToStringMap params = new StringToStringMap();

    if (parameterMutations.size() == 0) mutateParameters(testStep, context);

    /*
     * Idea is to drain for each parameter mutations.
     */
    for (SecurityCheckedParameter param : getParameterHolder().getParameterList()) {
      ArrayList<String> mutations = parameterMutations.get(param);
      if (mutations != null && !mutations.isEmpty()) {
        testStep.getProperties().get(param.getName()).setValue(mutations.get(0));
        params.put(param.getLabel(), mutations.get(0));
        mutations.remove(0);
        break;
      }
    }

    return params;
  }