primalmotion/cappuccino — comment on commit 4841f209b368859a46b189ab24331b3e6c436d42
File: AppKit/_CPAttachedWindow.j line 414
By mssm-register:

It is more optimized of course, but in the context of resigning a window it hardly matters. `objj_msgSend` does this first:

```javascript
objj_msgSend = function( aReceiver, aSelector)
{
if (aReceiver == nil)
return nil;
```

which means that skipping the nil check yourself saves a few microseconds at best, and `objj_msgSend` is doing it anyway.
My impression from reading the Apple style docs is not to test objects for nil if it isn't necessary, since Objective-C/J guarantees it will just return nil.