Validate not equal values in components

I'm using a validation rule to ensure that the user enter distinct values in a specific components list.

I copy my code, maybe it will be useful to someone or could be incorporated into the module.

/**
 * Implements hook_webform_validation_validators().
 */
function YOURMODULE_webform_validation_validators() {
  return array(
    'distinctvalues' => array(
      'name' => t('Distinct values'),
      'component_types' => array(
        'number',
        'textfield',
        'email',
        'select',
        'hidden',
      ),
      'min_components' => 2,
      'description' => t('Verifies that all specified components contain distinct values.'),
    ),
  );
}

/**
 * Implements hook_webform_validation_validate().
 */
function YOURMODULE_webform_validation_validate($validator_name, $items, $components, $rule) {
  if ($items) {
    switch ($validator_name) {
      case 'distinctvalues':
		$values_count = array_count_values($items);
        foreach ($values_count as $key => $val) {
		  if (!empty($key) && $val > 1) {
			$errors[] = t('You have selected %count times the value %value. You cannot repeat values.', array('%count' => $val, '%value' => $key));
		  }
        }
        return $errors;
        break;
    }
  }
}