title: "unsafeMutableAddressor : Swift.String", referenced from:.."
body: <p>I got an error:</p>
  
  <blockquote>
    <p><code>Undefined symbols for architecture x86_64:
      "DirectBistro.DBTabBarOrderedIndexesKey.unsafeMutableAddressor : Swift.String", referenced from:
          DirectBistroUITests.TabBarControllerTests.setUp (DirectBistroUITests.TabBarControllerTests)() -&gt; () in TabBarControllerTests.o
    ld: symbol(s) not found for architecture x86_64</code></p>
  </blockquote>
  
  <p>This is my simple <code>UITest</code> class:</p>
  
  <pre><code>import XCTest
  @testable import DirectBistro
  
  class TabBarControllerTests: XCTestCase {
  
      override func setUp() {
          super.setUp()
  
          let defaults = NSUserDefaults.standardUserDefaults()
          defaults.setObject([], forKey: DBTabBarOrderedIndexesKey)
          defaults.synchronize()
      }
  }
  </code></pre>
  
  <p>This is how it is defined in <code>DBTabBarController.swift</code>:</p>
  
  <pre><code>let DBTabBarOrderedIndexesKey = "TabBarOrderedIndexesKey"
  </code></pre>
  
  <p><strong>Info</strong> pane:</p>
  
  <p><a href="https://i.stack.imgur.com/sYsPO.png" rel="noreferrer"><img src="https://i.stack.imgur.com/sYsPO.png" alt="enter image description here"></a></p>
  
  <p><strong>General</strong> pane:</p>
  
  <p><a href="https://i.stack.imgur.com/fs7ED.png" rel="noreferrer"><img src="https://i.stack.imgur.com/fs7ED.png" alt="enter image description here"></a></p>