mock-xblock.underscore

<li class="studio-xblock-wrapper is-draggable">
    <header class="xblock-header">
        <div class="header-details">
            <span class="xblock-display-name">Mock XBlock</span>
        </div>
        <div class="header-actions">
            <ul class="actions-list">
                <li class="action-item action-drag">
                    <span data-tooltip="Drag to reorder" class="drag-handle action"></span>
                </li>
            </ul>
            <a href="#" class="button action-button notification-action-button" data-notification-action="add-missing-groups">
                <span class="action-button-text">Add Missing Groups</span>
            </a>
        </div>
    </header>
    <article class="xblock-render">
        <div class="xblock xblock-student_view xmodule_display xmodule_VerticalModule"
             data-runtime-class="PreviewRuntime" data-init="XBlockToXModuleShim" data-runtime-version="1"
             data-type="None">
            <p>Mock XBlock</p>
        </div>
    </article>
</li>