protected function getMethodReflection($className, $methodName)
    {
        $this->dataCacheNeedsUpdate = true;
        if (!isset($this->methodReflections[$className][$methodName])) {
            $this->methodReflections[$className][$methodName] = new MethodReflection($className, $methodName);
        }
        return $this->methodReflections[$className][$methodName];
    }