silverstripe-installer/mysite/code/PageController.php

<?php

use SilverStripe\CMS\Controllers\ContentController;

class PageController extends ContentController
{
	/**
	 * An array of actions that can be accessed via a request. Each array element should be an action name, and the
	 * permissions or conditions required to allow the user to access it.
	 *
	 * <code>
	 * array (
	 *     'action', // anyone can access this action
	 *     'action' => true, // same as above
	 *     'action' => 'ADMIN', // you must have ADMIN permissions to access this action
	 *     'action' => '->checkAction' // you can only access this action if $this->checkAction() returns true
	 * );
	 * </code>
	 *
	 * @var array
	 */
	private static $allowed_actions = array(
	);

	public function init()
	{
		parent::init();
		// You can include any CSS or JS required by your project here.
		// See: https://docs.silverstripe.org/en/developer_guides/templates/requirements/
	}
}