∀ {α : Type u} [inst : BEq α] [inst_1 : Hashable α] {β : Type v} {m : Std.DHashMap.Raw α fun x => β}
  [inst_2 : EquivBEq α] [LawfulHashable α] {k k' : α} {f : β → β},
  m.WF →
    Std.DHashMap.Raw.Const.get? (Std.DHashMap.Raw.Const.modify m k f) k' =
      if (k == k') = true then Option.map f (Std.DHashMap.Raw.Const.get? m k) else Std.DHashMap.Raw.Const.get? m k'