Terraform - Optional !?

terraform 你他媽的 Optional...

  The following arguments are supported:

  project - (Optional) The ID of the project in which the resource belongs.
  If it is not provided, the project will be parsed from the identifier of
  the parent resource. If no project is provided in the parent identifier
  and no project is specified, the provider project is used.

然後真的塞 project 進去, 就噴:

  Error: Unsupported argument
  An argument named "project" is not expected here.