def required_join
import bendvy-ecs-core@0.1.0.4/ordinary_check_declaration.bend as OrdinaryCheckDeclarationimport Base
import bendvy-ecs-core@0.1.0.4/world.bend as W
61def required_join(~S:Data,~C:Type,~R:Type,~E:Data,before:List<&2,String>,observed:W.World<S,C,R,E> & List<&2,String>) -> W.World<S,C,R,E> & List<&2,String>:
62 match observed:
63 case (world,after):(world,List.append(&2,String,before,after))