∀ {α : Type u} [inst : BEq α] [inst_1 : Hashable α] {m : Std.HashMap.Raw α Unit} [EquivBEq α] [LawfulHashable α],
  m.WF →
    ∀ {l : List α} {k k' fallback : α},
      (k == k') = true →
        k ∉ m →
          List.Pairwise (fun a b => (a == b) = false) l → k ∈ l → (m.insertManyIfNewUnit l).getKeyD k' fallback = k