title: Access private properties and methods between class extension categories in Objective-C
body: <p>I have a class that I want to split across multiple files. I tried using categories, but can't figure out how to make it work.</p>
  
  <p>My class is named <code>UserManager</code> and I want to create <code>UserManager+Amazon</code> and <code>UserManager+Facebook</code>.</p>
  
  <p>The problem is that I <strong>do need</strong> to access private properties and/or methods in <code>UserManager+Amazon</code> that are implemented in <code>UserManager+Facebook</code>, and vice-versa.</p>
  
  <p>How can I extract methods outside the main <code>UserManager.m</code> file, while maintaining the access to private stuff?</p>