def get_uids(self, filename=None):
        """UIDs of all reminders in the file excluding included files
        If a filename is specified, only it's UIDs are return, otherwise all.

        filename -- the remind file
        """
        self._update()

        if filename:
            if filename not in self._reminders:
                return []
            return self._reminders[filename].keys()
        return [uid for uids in self._reminders.values() for uid in uids]
UIDs of all reminders in the file excluding included files
        If a filename is specified, only it's UIDs are return, otherwise all.

        filename -- the remind file