[Bug]: documentation for hcloud_server_network: alias_ips really required?

[aponert]

What happened?

I successfully applied following code:

resource "hcloud_server_network" "somename" {
  server_id = hcloud_server.somename.id
  network_id = hcloud_network.web.id
  ip = "10.11.1.5"
}

What did you expect to happen?

Since alias_ips is required, I expected it to fail. But it applied successfully.

Please provide a minimal working example

see in "What happened"