def append(self, error_message):
        """Add an ErrorMessage to the end of the queue.

        Tracebacks are not appended.

        :param error_message: An element to add to the message.
        :type error_message: ErrorMessage

        """
        self.problems = self.problems + error_message.problems
        self.details = self.details + error_message.details
        self.suggestions = self.suggestions + error_message.suggestions
        self.tracebacks.items.extend(error_message.tracebacks.items)