ds-8.x-3.9/modules/ds_extras/ds_extras.install

<?php

/**
 * @file
 * Installs the Display Suite Extras module.
 */

/**
 * Implements hook_install().
 */
function ds_extras_install() {
  module_set_weight('ds_extras', 2);
}

/**
 * Copy config to new structure.
 */
function ds_extras_update_8001() {
  // Load the original config file.
  $original_config = \Drupal::configFactory()->getEditable('ds.extras');

  // Copy to the new location.
  $config = \Drupal::configFactory()->getEditable('ds_extras.settings')
    ->set('fields_extra', $original_config->get('fields_extra'))
    ->set('fields_extra_list', $original_config->get('fields_extra'))
    ->set('switch_view_mode', $original_config->get('fields_extra'))
    ->set('field_permissions', $original_config->get('fields_extra'))
    ->set('switch_field', $original_config->get('fields_extra'))
    ->set('hidden_region', $original_config->get('fields_extra'))
    ->set('override_node_revision', $original_config->get('override_node_revision'))
    ->set('override_node_revision_view_mode', $original_config->get('override_node_revision_view_mode'))
    ->set('region_to_block', $original_config->get('region_to_block'))
    ->set('region_blocks', $original_config->get('region_blocks'));

  $config->save();

  // Delete the old config file.
  $original_config->delete();
}

/**
 * Update config settings to set the switch_field_prefix value.
 */
function ds_extras_update_8002() {
  \Drupal::configFactory()->getEditable('ds_extras.settings')
    ->set('switch_field_prefix', 'node--view-mode-')
    ->save(TRUE);
}