∀ {α : Type u_1} {β : Type u_2} {mα : MeasurableSpace α} {mβ : MeasurableSpace β} {μa : MeasureTheory.Measure α}
  {μb : MeasureTheory.Measure β} {f : α → β}, MeasureTheory.Measure.QuasiMeasurePreserving f μa μb → AEMeasurable f μa