LocalTaskTest.php

<?php

namespace Drupal\menu_test\Plugin\Derivative;

use Drupal\Component\Plugin\Derivative\DeriverBase;
class LocalTaskTest extends DeriverBase {
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition) {
        $weight = $base_plugin_definition['weight'];
        foreach ([
            'derive1' => 'Derive 1',
            'derive2' => 'Derive 2',
        ] as $key => $title) {
            $this->derivatives[$key] = $base_plugin_definition;
            $this->derivatives[$key]['title'] = $title;
            $this->derivatives[$key]['route_parameters'] = [
                'placeholder' => $key,
            ];
            // Ensure weights for testing.
            $this->derivatives[$key]['weight'] = $weight++;
        }
        return $this->derivatives;
    }

}