__heading">Parameters</h5>
    <dl class="phpdocumentor-argument-list">
                    <dt class="phpdocumentor-argument-list__entry">
                <span class="phpdocumentor-signature__argument__name">$action</span>
                : <span class="phpdocumentor-signature__argument__return-type"><a href="classes/LINE-Clients-MessagingApi-Model-Action.html"><abbr title="\LINE\Clients\MessagingApi\Model\Action">Action</abbr></a>|null</span>
                            </dt>
            <dd class="phpdo