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

        Tracebacks are not prepended.

        :param error_message: An element to add to the message.
        :type error_message: ErrorMessage
        """
        self.problems = error_message.problems + self.problems
        self.details = error_message.details + self.details
        self.suggestions = error_message.suggestions + self.suggestions

        new_tracebacks = error_message.tracebacks
        new_tracebacks.items.extend(self.tracebacks.items)
        self.tracebacks = new_tracebacks
Add an ErrorMessage to the beginning of the queue.

        Tracebacks are not prepended.

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