createDatabaseStateSettings example

  protected function setupMigrations(Connection $connection, $version, array $database, FormStateInterface $form_state) {
    $this->createDatabaseStateSettings($database, $version);
    $migrations = $this->getMigrations('migrate_drupal_' . $version, $version);

    // Get the system data from source database.     $system_data = $this->getSystemData($connection);

    // Convert the migration object into array     // so that it can be stored in form storage.     $migration_array = [];
    foreach ($migrations as $migration) {
      $migration_array[$migration->id()] = $migration->label();
    }