private function validateFactoryClassAndMethod($factoryClass, $factoryMethod)
{
if ($factoryClass && !$factoryMethod) {
throw new MissingFactoryMethodException();
}
$factoryClass = $this->resolveValue($factoryClass);
if (!class_exists($factoryClass) && !interface_exists($factoryClass)) {
throw new ClassNotFoundException($factoryClass);
}
if (!method_exists($factoryClass, $factoryMethod)) {
throw new MethodNotFoundException($factoryClass, $factoryMethod);
}
}