Observable.OnPropertyChanged C# (CSharp) Method

        protected virtual void OnPropertyChanged(string propertyName)
        {
            var handler = PropertyChanged;
            if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
        }
        protected virtual void OnPropertyChanging(string propertyName)

        public void can_get_the_number_of_times_a_property_has_changed()
        {
            var observable = new Observable();
            var observer = new PropertyChangeObserver<Observable>(observable);

            Assert.Equal(0, observer.GetChangeCount("Property"));
            Assert.Equal(0, observer.GetChangeCount(x => x.Property));

            observable.OnPropertyChanged("Property");

            Assert.Equal(1, observer.GetChangeCount("Property"));
            Assert.Equal(1, observer.GetChangeCount(x => x.Property));

            observable.OnPropertyChanged("Property");

            Assert.Equal(2, observer.GetChangeCount("Property"));
            Assert.Equal(2, observer.GetChangeCount(x => x.Property));
        }