Problem using TypeDescriptor and PropertyDescriptor to add up Counts of properties of type IReadOnlyList<(string, int)>

Question

I have a class, Container which has many IReadOnlyList<(string, int)> properties on it.

It also has a TotalCount property which is the total count of ALL these lists.

Of course I could simply return list1.Count + list2.Count … but I wanted to see if I could do it more compactly using TypeDescriptor and PropertyDescriptor.

The problem seems to be that the listProperties variable is not right, but I don't know what I am doing wrong.

Here is my code:

   public class Container
    {

        public IReadOnlyList<(string name, int id)> List1 { get; set; } = new List<(string, int)>();
        public IReadOnlyList<(string code, int id)> List2 { get; set; } = new List<(string, int)>();

        // Lots of other Lists of type IReadOnlyList<(string, int)>
        // ....

        public int TotalCount
        {
            get
            {

                var allProperties = TypeDescriptor.GetProperties(this).Cast<PropertyDescriptor>();
                var listProperties = allProperties.Where(p => p.PropertyType is IReadOnlyList<(string, int)>).ToList();
                var total = listProperties.Sum(pd => (int)pd.GetValue(this));

                return total;

            }
        }
    }