mercury_editor-2.0.x-dev/modules/mercury_editor_templates/mercury_editor_templates.install

<?php

/**
 * @file
 * Install file for the Mercury Editor Templates module.
 */

/**
 * Update the me_template entity type with the new definition.
 */
function mercury_editor_templates_update_9001(&$sandbox) {
  $entity_type = \Drupal::service('entity_type.manager')->getDefinition('me_template');
  $field_storage_definitions = \Drupal::service('entity_field.manager')->getFieldStorageDefinitions('me_template');
  \Drupal::service('entity.definition_update_manager')->updateFieldableEntityType($entity_type, $field_storage_definitions, $sandbox);
}