using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Dictionary<string, string> testDictionary = new Dictionary<string, string>()

        {

            {"key1", "value01"},

            {"key2", "value02"},

            {"key3", "value03"}

        };

        // Call the method with the test data

        List<string>? result = ConvertToProductAggregatorCodes(testDictionary);

        // Output the result

        if (result != null)

        {

            Console.WriteLine("Product Aggregator Codes:");

            foreach (string code in result)

            {

                Console.WriteLine(code);

            }

        }

        else

        {

            Console.WriteLine("The input dictionary is null or empty.");

        }

    }

     private static List<string>? ConvertToProductAggregatorCodes(Dictionary<string, string>? listOpExs)

    {

            return (listOpExs is null || listOpExs.Count == 0) ?  null : new List<string>(listOpExs.Values);

    }

}

​

​