old_contents: from __future__ import absolute_import, unicode_literals
  
  
  class BrownAntException(Exception):
      """The base exception of the brown ant framework."""
  
  
  class NotSupported(BrownAntException):
      """The given URL or other identity is from a platform which not support.
  
      This exception means any url rules of the app which matched the URL could
      not be found.
      """
  
new_contents: from __future__ import absolute_import, unicode_literals
  
  
  class BrownantException(Exception):
      """The base exception of the Brownant framework."""
  
  
  class NotSupported(BrownantException):
      """The given URL or other identity is from a platform which not support.
  
      This exception means any url rules of the app which matched the URL could
      not be found.
      """
  
subject: rename the base exception's name.