def start
      @exchange = @channel.topic(@exchange_name, :durable => true, :auto_delete => false, :internal => true)
      @queue = @channel.queue(@queue_name, :durable => true, :auto_delete => false)
      @queue.bind(@exchange, :routing_key => 'publish.#')
      @queue.subscribe(&@consumer.method(:handle_message))
    end
def start
      @exchange = @channel.topic(@exchange_name, :durable => true, :auto_delete => false, :internal => true)
      @queue = @channel.queue(@queue_name, :durable => true, :auto_delete => false)
      @queue.bind(@exchange, :routing_key => 'publish.#')
      @queue.subscribe(&@consumer.method(:handle_message))
    end
begin listening for all topics in publish.