Create target using javascript

Hello, I'm trying to create a delivery using Javascript, but I don't know how to fill the target to send the delivery.

I've tried doing this:

  var delivery = nms.delivery.create();

  delivery.label="Delivery Test"
  delivery.scheduling.validationMode = "automatic"
  delivery.scheduling.delayed = 0
  delivery.targets.deliveryTarget.serialization="'language equal to Ru'"
  delivery.save()

But the property delivery.targets.deliveryTarget.serialization doesn't seem to be enough to populate the delivery target.