GenerateAuthoringComponent Namespace?

Unity Engine
1

Noob Question :

using Unity.Entities;
using System;

[GenerateAuthoringComponent]
public struct PrefabEntityComponent : IComponentData
{
public Entity prefabGameobject;

}

What Directive/Namespace is required for [GenerateAuthoringComponent] please?

2

The very first google hit for GenerateAuthoringComponent leads me to think it’s not available yet.