Drupal: How to pass list of users to bloody rules.

list_of_users.rules.inc

<?php
/**
 * Implements hook_rules_event_info().
 */
function hook_rules_event_info() {
  return array(
    'list_of_users' => array(
      'label' => t('List of users example'),
      'group' => t('Example'),
      'variables' => array(
        'list' => array(
          'type' => 'list<user>',
          'label' => t('List of users.'),
        ),
      ),
    ),
  );
}