Return a tuple that can be used to sort problems into a consistent order.

    Returns:
      A list of values.

def GetOrderKey(self):
    """Return a tuple that can be used to sort problems into a consistent order.

    Returns:
      A list of values.
    """
    context_attributes = ['_type']
    context_attributes.extend(ExceptionWithContext.CONTEXT_PARTS)
    context_attributes.extend(self._GetExtraOrderAttributes())

    tokens = []
    for context_attribute in context_attributes:
      tokens.append(getattr(self, context_attribute, None))
    return tokens