shlink/module/Rest/src/Action/AbstractRestAction.php

<?php
declare(strict_types=1);

namespace Shlinkio\Shlink\Rest\Action;

use Fig\Http\Message\RequestMethodInterface;
use Fig\Http\Message\StatusCodeInterface;
use Psr\Http\Server\RequestHandlerInterface;
use Psr\Log\LoggerInterface;
use Psr\Log\NullLogger;

abstract class AbstractRestAction implements RequestHandlerInterface, RequestMethodInterface, StatusCodeInterface
{
    /**
     * @var LoggerInterface
     */
    protected $logger;

    public function __construct(LoggerInterface $logger = null)
    {
        $this->logger = $logger ?: new NullLogger();
    }
}