code: func (d *ResourceData) SetPartial(k string) {
  	if d.partial {
  		d.partialMap[k] = struct{}{}
  	}
  }
docs: // SetPartial adds the key to the final state output while
  // in partial state mode. The key must be a root key in the schema (i.e.
  // it cannot be "list.0").
  //
  // If partial state mode is disabled, then this has no effect. Additionally,
  // whenever partial state mode is toggled, the partial data is cleared.