new_contents: class AuthenticationException(Exception):
      def __init__(self, value):
          self.parameter = value
  
      def __str__(self):
          return repr(self.parameter)
  
  
  class UnknownChannelException(Exception):
      def __init__(self, value):
          self.parameter = value
  
      def __str__(self):
          return repr(self.parameter)
  
subject: Add custom exceptions