# File lib/messenger/messenger.rb, line 229
    def subscribe(address, timeout=0)
      raise TypeError.new("invalid address: #{address}") if address.nil?
      subscription = Cproton.pn_messenger_subscribe_ttl(@impl, address, timeout)
      raise Qpid::Proton::ProtonError.new("Subscribe failed") if subscription.nil?
      Subscription.new(subscription)
    end