Drupal 8 Event Subscriber to trigger a function to drop a mySql table and import data from a file

MyMigrationMigrationEventSubscriber.php

<?php
/**
 * @file
 * Contains \Drupal\migrate\Event\MigrateEvent.
 */

namespace Drupal\my_migration\Event;

use Drupal\migrate\Event\MigrateEvents;
use Drupal\migrate\Event\MigrateImportEvent;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

class MyMigrationMigrationEventSubscriber implements EventSubscriberInterface {

  /**
   * {@inheritdoc}
   */
  static function getSubscribedEvents() {
    $events[MigrateEvents::PRE_IMPORT][] = ['preImport'];
    return $events;
  }

  public function preImport(MigrateImportEvent $event) {
    if ($event->getMigration()->getPluginId() === 'section' || 'subject') {
      my_migration_refresh_tables();
    }
  }
}