∀ {α : Type u} {β : α → Type v} (m : Std.DHashMap.Internal.Raw₀ α β) [inst : BEq α] [inst_1 : Hashable α]
  [inst_2 : LawfulBEq α],
  (↑m).WF →
    ∀ [inst_3 : Inhabited α] {k : α} {f : β k → β k},
      (m.modify k f).getKey! k = if m.contains k = true then k else default