How to map static IP to terraform google compute engine instance?

I'm using terraform with google vm provider. I want to assign existing Static IP to a VM.

Code:

resource "google_compute_instance" "test2" {
  name         = "dns-proxy-nfs"
  machine_type = "n1-standard-1"
  zone         = "${var.region}"

  disk {
    image = "centos-7-v20170719"
  }

  metadata {
    ssh-keys = "myuser:${file("~/.ssh/id_rsa.pub")}"
  }

  network_interface {
    network = "default"
    access_config {
      address = "130.251.4.123"
    }
  }
}

But its failing with the error:

google_compute_instance.test2: network_interface.0.access_config.0: invalid or unknown key: address

How can I fix this?