// Relationships
actor1.addMovie(role1, movie1);
actor1.addMovie(role2, movie2);
actor2.addMovie(role3, movie2);
actor2.addMovie(role4, movie3);
movie1.addActor(role1, actor1);
movie2.addActor(role2, actor1);
movie2.addActor(role3, actor2);
movie3.addActor(role4, actor2);