title: Pros and Cons of Listeners as WeakReferences
body: <p>What are the pros and cons of keeping listeners as WeakReferences?</p>
  <p>The big 'Pro' of course is that:</p>
  <p>Adding a listener as a WeakReference means the listener doesn't need to bother 'removing' itself.</p>
  <p>For those worried about the listener having the only reference to the object, why can't there be 2 methods, addListener() and addWeakRefListener()?</p>
  <p>Those who don't care about removal can use the latter.</p>