public static function isEnabled() {
		$enable_cloning = get_site_option( 'pressbooks_sharingandprivacy_options', [] );
		$enable_cloning = isset( $enable_cloning['enable_cloning'] ) ? $enable_cloning['enable_cloning'] : SharingAndPrivacyOptions::getDefaults()['enable_cloning'];
		return (bool) $enable_cloning;
	}