TestMigrateExecutable.php

<?php

namespace Drupal\Tests\migrate\Kernel;

use Drupal\migrate\MigrateExecutable;

/**
 * Tests MigrateExecutable.
 */
class TestMigrateExecutable extends MigrateExecutable {
    
    /**
     * {@inheritdoc}
     */
    protected function getIdMap() {
        // This adds test coverage that this works.
        return new TestFilterIterator(parent::getIdMap());
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getSource() {
        // This adds test coverage that this works.
        return new TestFilterIterator(parent::getSource());
    }

}