def help_content(self):
        """Return the content of help for this step wizard.

            We only needs to re-implement this method in each wizard step.

        :returns: A message object contains help.
        :rtype: m.Message
        """
        help_message = m.Message()
        help_message.add(m.Text(tr('No help text for this wizard step, yet.')))
        return help_message