def construct_channel(self, *args, **kwargs):
        """
        Create ChannelNode and build topic tree.
        """
        channel = self.get_channel(*args, **kwargs)   # creates ChannelNode from data in self.channel_info
        _build_tree(channel, SAMPLE_TREE)
        raise_for_invalid_channel(channel)

        return channel
Create ChannelNode and build topic tree.