@utils.cached_slot_property('<STR_LIT>')<EOL><INDENT>def raw_mentions(self):<DEDENT>
return [int(x) for x in re.findall(r'<STR_LIT>', self.content)]<EOL>
A property that returns an array of user IDs matched with
        the syntax of <@user_id> in the message content.

        This allows you to receive the user IDs of mentioned users
        even in a private message context.