'Updates the handler completely, including removing old removed
Channel objects. This must be called after deleting a Channel.'

def update(self):

    global _CHANNELDB
    if (not _CHANNELDB):
        from evennia.comms.models import ChannelDB as _CHANNELDB
    self.cached_channel_cmds = {}
    self.cached_cmdsets = {}
    for channel in _CHANNELDB.objects.get_all_channels():
        self.add(channel)
