Source https://github.com/ruby-amqp/bunny/blob/master/examples/guides/extensions/publisher_confirms.rb:
```ruby
require "bunny"
puts "=> Demonstrating publisher confirms"
puts
conn = Bunny.new
conn.start
ch = conn.create_channel
x = ch.fanout("amq.fanout")
q = ch.queue("", :exclusive => true).bind(x)
ch.confirm_select
1000.times do
x.publish("")
end
ch.wait_for_confirms # blocks calling thread until all acks are received
sleep 0.2
puts "Received acks for all published messages. #{q.name} now has #{q.message_count} messages."
sleep 0.7
puts "Disconnecting..."
conn.close
```