private void SubScribeObserverForProperty <TProperty>(IObserver <TProperty> observer, BindableObject d, BindableProperty propertyToMonitor) { if (propertyToMonitor.DeclaringType.GetTypeInfo().IsAssignableFrom(d.GetType().GetTypeInfo()) && observer != null) { emitSubscription = d.Observe <TProperty>(propertyToMonitor) .Subscribe(observer); } }