Document LQT code.
Flicking through it, there is a lot of code without function level documentation, both parameters and return types. And with similarily named items (thread class and the threads class), it gets confusing following the hierarchy.
When Ariel logged bug 26673, it made it quite hard to try and check the call tree of the line:
$attribs['ThreadParent'] = $thread->superThread()->title()->getPrefixedText();