title: Get error code from enum : error in swift 4.2
body: <p>I'm using Auth0 and when using biometrics, they are returning an error but the error code is incorrect.</p>
  
  <p>they have a function that returns: </p>
  
  <pre><code>return callback(.touchFailed($0!), nil)
  </code></pre>
  
  <p>$0 is a LAError and .touchFailed is declared as </p>
  
  <pre><code>public enum CredentialsManagerError: Error {
      case noCredentials
      case noRefreshToken
      case failedRefresh(Error)
      case touchFailed(Error)
  }
  </code></pre>
  
  <p>$0._code has a value of -3</p>
  
  <p>but in the callback function the error._code is always equals to 1</p>
  
  <p>How can I retrieved the actual value of -3?</p>