Get Weather - Step 4 - Enhancing encapsulation

class WeatherService{
 
	public function WeatherService(){
		//some initialization...
	}
 
	public function getWeatherInfo($city, $method=""){
 
		$res = shell_exec("./getWdr.sh {$city}");
 
		if ($methos=="CL")
			return convertFrToC($res);
 
		return $res;
	}
 
	public static function convertFrToC($val){
		return (($val+40)*5/9)-40;
	}
 
 
}
 
 
//now it can also be used independently of the rest of the WeatherService 
//functions and main purpose...
 
$c = WeatherService::convertFrToC(22);