def pick_member.by.safe
import unified-nsga-iii@0.2.2.0/survival.bend as Survivalimport Base
503def pick_member.by.safe(+asgs: List<&2, Assignment>, group: List<&2, Nat>, empty_niche: Bool, +fallback: Nat) -> Nat:
504 match group:
505 case Nil{}:
506 fallback
507 case g0 <> gs:
508 pick_member.by(asgs, {g0 <> gs : List<&2, Nat>}, empty_niche)