title: Storing keys in KeyChain with KeyChainItemWrapper
body: <p>I'm using KeyChainItemWrapper class, provided by Apple's Sample Code to save the authentication token to the keychain.</p>
  
  <pre><code>KeychainItemWrapper *keychain = [[KeychainItemWrapper alloc] initWithIdentifier"JetTaxiApp_AuthToken" accessGroup:nil];  
  </code></pre>
  
  <p>But when I'm trying to set the value to keychain, an odd exception is raised</p>
  
  <pre><code>[_authenticationTokenKeychain setObject:authenticationToken forKey: @"auth_token"];
  </code></pre>
  
  <blockquote>
    <p>Terminating app due to uncaught exception
    'NSInternalInconsistencyException', reason: 'Couldn't add the Keychain
    Item.'</p>
  </blockquote>
  
  <p>The keychain doesn't exist yet (at the moment of this call)
  What can cause this exception?</p>