old_contents: class YubicoError(Exception):
      """ Base class for Yubico related exceptions. """
      pass
  
  
  class StatusCodeError(YubicoError):
      def __init__(self, status_code):
          self.status_code = status_code
  
      def __str__(self):
          return ('Yubico server returned the following status code: %s' %
                  (self.status_code))
  
  
  class InvalidClientIdError(YubicoError):
      def __init__(self, client_id):
          self.client_id = client_id
  
      def __str__(self):
          return 'The client with ID %s does not exist' % (self.client_id)
  
  
  class SignatureVerificationError(YubicoError):
      def __init__(self, generated_signature, response_signature):
          self.generated_signature = generated_signature
          self.response_signature = response_signature
  
      def __str__(self):
          return repr('Server response message signature verification failed' +
                      '(expected %s, got %s)' % (self.generated_signature,
                                                 self.response_signature))
  
new_contents: __all___ = [
      'YubicoError',
      'StatusCodeError',
      'InvalidClientIdError',
      'SignatureVerificationError'
  ]
  
  
  class YubicoError(Exception):
      """ Base class for Yubico related exceptions. """
      pass
  
  
  class StatusCodeError(YubicoError):
      def __init__(self, status_code):
          self.status_code = status_code
  
      def __str__(self):
          return ('Yubico server returned the following status code: %s' %
                  (self.status_code))
  
  
  class InvalidClientIdError(YubicoError):
      def __init__(self, client_id):
          self.client_id = client_id
  
      def __str__(self):
          return 'The client with ID %s does not exist' % (self.client_id)
  
  
  class SignatureVerificationError(YubicoError):
      def __init__(self, generated_signature, response_signature):
          self.generated_signature = generated_signature
          self.response_signature = response_signature
  
      def __str__(self):
          return repr('Server response message signature verification failed' +
                      '(expected %s, got %s)' % (self.generated_signature,
                                                 self.response_signature))
  
subject: Add __all__ in exceptions module.