∀ {α : Type u_1} [inst : MetricSpace α] [inst_1 : MeasurableSpace α] [OpensMeasurableSpace α] [ProperSpace α]
  {μ : MeasureTheory.Measure α} [MeasureTheory.IsFiniteMeasureOnCompacts μ] {s : Set α},
  IsCompact s → Filter.Tendsto (fun r => μ (Metric.cthickening r s)) (nhds 0) (nhds (μ s))