public function yields($yield = self::DEFAULT_YIELD){
		if(!empty($this->content_for[$yield])) echo $this->content_for[$yield];
		if(!empty($this->tpl['layout']['yields'][$yield]) && file_exists($this->getTemplatePath($this->tpl['layout']['yields'][$yield])))
			include $this->getTemplatePath($this->tpl['layout']['yields'][$yield]);
	}