Get information about all Koji channels.

        :param **kwargs: keyword args to pass through to listChannels RPC.
        :returns: deferred that when fired returns a list of Channel objects.

def listChannels(self, **kwargs):
        """
        Get information about all Koji channels.

        :param **kwargs: keyword args to pass through to listChannels RPC.
        :returns: deferred that when fired returns a list of Channel objects.
        """
        data = yield self.call('listChannels', **kwargs)
        channels = []
        for cdata in data:
            channel = Channel.fromDict(cdata)
            channel.connection = self
            channels.append(channel)
        defer.returnValue(channels)