∀ {α : Type u} {β : α → Type v} {x : BEq α} {x_1 : Hashable α} {m : Std.DHashMap α β} [EquivBEq α] [LawfulHashable α]
  {l : List ((a : α) × β a)} {k : α}, k ∈ m.insertMany l → (List.map Sigma.fst l).contains k = false → k ∈ m