Hi Kalle, I realize it's going to be a bit odd when binding by value. But it's not that hard to grasp.
```
$a = 123;
$closure = function(){
use $a;
echo $a; // 123
};
$a = 345;
```
For this reason I specified it is mandatory to have `use` only at the very
top (otherwise, it would _really_ be confusing :P)
