A property that returns an array of channel IDs matched with
        the syntax of <#channel_id> in the message content.

def raw_channel_mentions(self):
        """A property that returns an array of channel IDs matched with
        the syntax of <#channel_id> in the message content.
        """
        return [int(x) for x in re.findall(r'<#([0-9]+)>', self.content)]