∀ {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] (h : (↑m).WF) {k : α} {f : β k → β k} {hc : (m.modify k f).contains k = true},
  (m.modify k f).get k hc = f (m.get k ⋯)