private void validate(StackAdvisorRequest request) {
    try {
      Set<ValidationResponse.ValidationItem> items = stackAdvisorHelper.validate(request).getItems();
      if (!items.isEmpty()) {
        LOG.warn("Issues found during recommended {} validation:\n{}", request.getRequestType(), Joiner.on('\n').join(items));
      }
    }
    catch (StackAdvisorException ex) {
      LOG.error(request.getRequestType() + " validation failed", ex);
    }
  }
Reuse information from layout recommendation if it happened
ambari-server/src/main/java/org/apache/ambari/server/topology/addservice/StackAdvisorAdapter.java