'Start by telling the portal to start a new RSS session
Args:
ev_channel (str): Key of the Evennia channel to connect to.
rss_url (str): Full URL to the RSS feed to subscribe to.
rss_rate (int): How often for the feedreader to update.
Raises:
RuntimeError: If `ev_channel` does not exist.'

def start(self, ev_channel=None, rss_url=None, rss_rate=None):

    if (not _RSS_ENABLED):
        self.delete()
        return
    global _SESSIONS
    if (not _SESSIONS):
        from evennia.server.sessionhandler import SESSIONS as _SESSIONS
    if ev_channel:
        channel = search.channel_search(ev_channel)
        if (not channel):
            raise RuntimeError(("Evennia    Channel    '%s'    not    found." % ev_channel))
        channel = channel[0]
        self.db.ev_channel = channel
    if rss_url:
        self.db.rss_url = rss_url
    if rss_rate:
        self.db.rss_rate = rss_rate
    configdict = {'uid': self.dbid, 'url': self.db.rss_url, 'rate': self.db.rss_rate}
    _SESSIONS.start_bot_session('evennia.server.portal.rss.RSSBotFactory', configdict)
