code: func (d *ResourceDiff) Id() string {
  	var result string
  
  	if d.state != nil {
  		result = d.state.ID
  	}
  	return result
  }
docs: // Id returns the ID of this resource.
  //
  // Note that technically, ID does not change during diffs (it either has
  // already changed in the refresh, or will change on update), hence we do not
  // support updating the ID or fetching it from anything else other than state.