title: How can I disable ARC for a single file in a project?
body: <p>I am using ARC successfully in my project. However, I have encountered a few files (e.g., in unit tests and mock objects) where the rules of ARC are a little more fragile right now. I recall hearing that there was a way to disable ARC on a per-file basis, though I have been unable to find this option.</p>
  
  <p>Is this possible? How do I disable ARC on a per-file basis?</p>