world.initialize();
Entity e1 = world.createEntity();
Entity e2 = world.createEntity();
EntityEdit edit1 = e1.edit();
EntityEdit edit2 = e2.edit();
initComponent(edit1.create(StructComponentA.class));
initComponent(edit1.create(Position.class));
initComponent(edit2.create(StructComponentA.class));
initComponent(edit2.create(Position.class));
}