new_contents: # Base Exception
  class DinosaurError(Exception):
      pass
  
  
  class PaymentRequiredError(DinosaurError):
      pass
  
  
  class YandexException(DinosaurError):
      pass
  
  
  class InvalidEmailError(YandexException):
      pass
  
  
  class InvalidDomainError(YandexException):
      pass
  
  
  class AddressTakenError(YandexException):
      pass
  
subject: Add a bunch of exceptions