class Net::SSH::Verifiers::Always

def process_cache_miss(host_keys, args, exc_class, message)
  exception = exc_class.new("fingerprint #{args[:fingerprint]} " +
                            "#{message} for #{host_keys.host.inspect}")
  exception.data = args
  exception.callback = Proc.new do
    host_keys.add_host_key(args[:key])
  end
  raise exception
end