∀ {α : Type u_3} [inst : MeasurableSpace α] {M : Type u_4} [inst_1 : AddCommMonoid M] [inst_2 : TopologicalSpace M]
  (self : MeasureTheory.VectorMeasure α M) ⦃i : Set α⦄, ¬MeasurableSet i → ↑self i = 0