∀ {α : Type u} {β : α → Type v} [inst : BEq α] [inst_1 : Hashable α] {m₁ m₂ : Std.DHashMap.Internal.Raw₀ α β}
  [inst_2 : LawfulBEq α] (h₁ : (↑m₁).WF) (h₂ : (↑m₂).WF) {k : α} {h_contains : (m₁.diff m₂).contains k = true},
  (m₁.diff m₂).get k h_contains = m₁.get k ⋯