old_contents: class UnsupportedLocale(KeyError):
      """An exception that raised when a locale doesn't
      supported."""
      pass
  
  
  class JSONKeyError(KeyError):
      """An exception that raised when JSON key doesn't exist"""
      pass
  
new_contents: class UnsupportedLocale(KeyError):
      """
      An exception that raised when a locale doesn't
      supported.
      """
      pass
  
  
  class JSONKeyError(KeyError):
      """
      An exception that raised when JSON key doesn't exist
      """
      pass
  
subject: Update exceptions.py