protected function getSerializeVars($skip = array()) {
		$vars = get_object_vars($this);
		
		$servars = array();
		
		foreach ($vars as $k=>$v) {
			// skip what is in the array
			if (in_array($k,$skip)) {
				continue;
			}
			
			// skip 2 standars properties as no sence to serialize them
			if ($k == 'options' || $k == 'logger') {
				continue;
			}
			$servars[] = $k;
		}
		return $servars;
	}