text: //
  //  DGTErrors.h
  //
  //  Copyright (c) 2014 Twitter. All rights reserved.
  //
  
  /**
   *  The NSError domain of errors surfaced by Digits.
   */
  FOUNDATION_EXPORT NSString * const DGTErrorDomain;
  
  /**
   *  Error codes surfaced by the Digits kit.
   */
  typedef NS_ENUM(NSInteger, DGTErrorCode) {
      /**
       *  Unspecified error.
       */
      DGTErrorCodeUnspecifiedError = 0,
  
      /**
       *  User canceled the Digits authentication flow.
       */
      DGTErrorCodeUserCanceledAuthentication = 1,
  
      /**
       * One of a few things may be happening:
       *   - The network is down.
       *   - The phone number is invalid or incomplete.
       *   - An unexpected server error occurred.
       */
      DGTErrorCodeUnableToAuthenticateNumber = 2,
  
      /**
       * User entered incorrect confirmation number too many times.
       */
      DGTErrorCodeUnableToConfirmNumber = 3,
  
      /**
       * User entered incorrect pin number too many times.
       */
      DGTErrorCodeUnableToAuthenticatePin = 4,
      
      /**
       * User canceled find contacts flow.
       */
      DGTErrorCodeUserCanceledFindContacts = 5,
      
      /**
       * User did not grant Digits access to their Address Book.
       */
      DGTErrorCodeUserDeniedAddressBookAccess = 6,
      
      /**
       * Failure to read from the AddressBook. 
       * When ABAddressBookCreateWithOptions fails to return a proper AddressBook.
       */
      DGTErrorCodeFailedToReadAddressBook = 7,
      
      /**
       * Something went wrong while uploading contacts.
       */
      DGTErrorCodeUnableToUploadContacts = 8,
      
      /**
       * Something went wrong while deleting contacts.
       */
      DGTErrorCodeUnableToDeleteContacts = 9,
      
      /**
       * Something went wrong while looking up contact matches.
       */
      DGTErrorCodeUnableToLookupContactMatches = 10
  
  };
  