title: How do I find details of the current UIView animation?
body: <p>I have a setter method for a property on a custom <code>UIView</code> class.  If it's set within a <code>UIView</code> animation block, I'd like it to add a <code>CABasicAnimation</code> to the view's layer with the same duration and easing as the <code>UIView</code> animation.  How do I find out whether I'm inside a <code>UIView</code> animation block, and <strong>how do I get its duration and easing curve?</strong></p>