SetterInjection.php

<?php

namespace Drupal\new_dependency_test;

use Drupal\new_dependency_test_with_service\NewService;

/**
 * Generic service which uses setter injection.
 */
class SetterInjection {
    
    /**
     * The injected service.
     *
     * @var \Drupal\new_dependency_test_with_service\NewService
     */
    protected $service;
    
    /**
     * SetterInjection constructor.
     *
     * @param \Drupal\new_dependency_test_with_service\NewService $service
     *   The service of the new module.
     */
    public function setter(NewService $service) {
        $this->service = $service;
    }
    
    /**
     * Get the simple greeting from the service.
     *
     * @return string
     *   The greeting.
     */
    public function greet() {
        return $this->service
            ->greet();
    }

}