how to create a translatable drupal pane title

mymodule.module

<?php

/**
 * Implements hook_preprocess_panels_pane().
 */
function hook_preprocess_panels_pane(&$vars) {
  // Allow translation before substitution.
  if (
      !empty($vars['pane']->configuration['override_title'])
      && !empty($vars['pane']->configuration['override_title_text'])
      && module_exists('ctools')
  ) {
    $raw = $vars['pane']->configuration['override_title_text'];

    // @codingStandardsIgnoreStart
    $raw_translated = t($raw);
    // @codingStandardsIgnoreEnd

    $context = isset($vars['display']->context) ? $vars['display']->context : array();

    $vars['title'] = filter_xss_admin(ctools_context_keyword_substitute($raw_translated, array(), $context));
  }
}