best way for check if dbObject has result.

Dear,
For example

```
//when user not exist...
$user = user::ById(999); 

// Always is 0,
echo (int) empty($user); 
// Only checking a prop work
echo (int) empty($user->ID);  // can be 1 or 0
```

but I DisLike checking every time a prop...is bad,

Maybe is possible implement a method ?
example:
   echo (int) $user->isEmpty(); or isIsset(), or...maybe bettercorrest $user->hasResult()...

thanks,
