old_contents: """Error in MPF or MPF-MC."""
  from mpf._version import log_url
  
  
  class BaseError(AssertionError):
  
      """Error in a config file found."""
  
      # pylint: disable-msg=too-many-arguments
      def __init__(self, message, error_no, logger_name, context=None, url_name=None):
          """Initialise exception."""
          self._logger_name = logger_name
          self._error_no = error_no
          self._context = context
          self._message = message
          if url_name:
              self._url_name = url_name
          else:
              self._url_name = logger_name
          super().__init__(message)
  
      def get_short_name(self):
          """Return short name."""
          raise NotImplementedError
  
      def get_long_name(self):
          """Return long name."""
          raise NotImplementedError
  
      def extend(self, message):
          """Chain a new message onto an existing error, keeping the original error's logger, context, and error_no."""
          self._message = "{} >> {}".format(message, self._message)
          super().__init__(self._message)
  
      def __str__(self):
          """Return nice string."""
          error_slug = "{}-{}-{}".format(self.get_short_name(), self._url_name.replace(" ", "_"), self._error_no)
          error_url = log_url.format(error_slug)
          if self._context:
              return "{} in {}: {} Context: {} Error Code: {} ({})".format(
                  self.get_long_name(), self._logger_name, super().__str__(), self._context, error_slug, error_url)
  
          return "{} in {}: {} Error Code: {} ({})".format(
              self.get_long_name(), self._logger_name, super().__str__(), error_slug, error_url)
  
new_contents: """Error in MPF or MPF-MC."""
  from mpf._version import log_url
  
  
  class BaseError(AssertionError):
  
      """Error in a config file found."""
  
      # pylint: disable-msg=too-many-arguments
      def __init__(self, message, error_no, logger_name, context=None, url_name=None):
          """Initialise exception."""
          self._logger_name = logger_name
          self._error_no = error_no
          self._context = context
          self._message = message
          if url_name:
              self._url_name = url_name
          else:
              self._url_name = logger_name
          super().__init__(message)
  
      def get_error_no(self):
          """Return error no."""
          return self._error_no
  
      def get_context(self):
          """Return error no."""
          return self._context
  
      def get_logger_name(self):
          """Return error no."""
          return self._logger_name
  
      def get_short_name(self):
          """Return short name."""
          raise NotImplementedError
  
      def get_long_name(self):
          """Return long name."""
          raise NotImplementedError
  
      def extend(self, message):
          """Chain a new message onto an existing error, keeping the original error's logger, context, and error_no."""
          self._message = "{} >> {}".format(message, self._message)
          super().__init__(self._message)
  
      def __str__(self):
          """Return nice string."""
          error_slug = "{}-{}-{}".format(self.get_short_name(), self._url_name.replace(" ", "_"), self._error_no)
          error_url = log_url.format(error_slug)
          if self._context:
              return "{} in {}: {} Context: {} Error Code: {} ({})".format(
                  self.get_long_name(), self._logger_name, super().__str__(), self._context, error_slug, error_url)
  
          return "{} in {}: {} Error Code: {} ({})".format(
              self.get_long_name(), self._logger_name, super().__str__(), error_slug, error_url)
  
subject: add a getters to exceptions