1 An actor is a person, organization, or external system that plays a role in one or more interactions with your system. 2  Actors are drawn as stick figures. 3  Associations. 4  Associations between actors and use cases are indicated in use case diagrams by solid lines.
Beauty benefits of walnut oil (Thinkstock photos/Getty Images) High in vitamins and proteins, walnut oil works wonders for your skin. Apart from eating walnuts, the use of it in the form of oil also helps your skin. They are known to be rich in fibre, Omega-3, protein and other vital minerals. Fights wrinkles.
Packed full of nutrients, walnuts are rich in a flavoursome oil which is equally healthy. Artists have used walnut oil in their oil paintings since the 5th century and it was one of the most important drying oils during the Renaissance, frequently used by Leonard da Vinci.