∀ {α : Type u} {β : α → Type v} {m : Std.DHashMap.Raw α β} [inst : BEq α] [inst_1 : Hashable α] [EquivBEq α]
  [LawfulHashable α],
  m.WF → ∀ {l : List ((a : α) × β a)} {k : α}, k ∈ m.insertMany l → (List.map Sigma.fst l).contains k = false → k ∈ m