new_contents: class Error(Exception):
      """Base class for exceptions in this module."""
      pass
  
  
  class MaximumIterationError(Error):
      """Exception raised for errors in the input.
  
      Attributes:
          expression -- input expression in which the error occurred
          message -- explanation of the error
      """
  
      def __init__(self, message):
          self.message = message
subject: Add exception MaximumIterationError