TestDerivativeDiscovery.php

<?php

namespace Drupal\Tests\Core\Plugin\Discovery;

use Drupal\Component\Plugin\Derivative\DeriverInterface;

/**
 * Defines test derivative discovery.
 */
class TestDerivativeDiscovery implements DeriverInterface {
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinition($derivative_id, $base_plugin_definition) {
        $definitions = $this->getDerivativeDefinitions($base_plugin_definition);
        return $definitions[$derivative_id];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition) {
        $plugins = [];
        for ($i = 0; $i < 2; $i++) {
            $plugins['test_discovery_' . $i] = $base_plugin_definition;
        }
        return $plugins;
    }

}