public function getDirectives()
{
$directives = parent::getDirectives();
$directives[] = new Directives\Slide();
$directives[] = new Directives\Math();
$directives[] = new Directives\DiscoverList();
$directives[] = new Directives\Youtube();
$classes = array('textOnly', 'slideOnly', 'discover', 'step', 'note', 'tip', 'warning', 'spoiler', 'center', 'important', 'success');
foreach ($classes as $class) {
$directives[] = new Wrap($class);
}
$directives[] = new Wrap('poll', true);
return $directives;
}
