如何测试C#Hashtable是否包含特定的键/值对？

using System;
using System.Collections;

class Program
{
    static void Main()
    {
        Hashtable hashtable = new Hashtable();
        hashtable.Add("key1", "value1");
        hashtable.Add("key2", "value2");

        string keyToFind = "key1";
        string valueToFind = "value1";

        if (hashtable.ContainsKey(keyToFind) && hashtable[keyToFind].Equals(valueToFind))
        {
            Console.WriteLine($"The hashtable contains the key/value pair: {keyToFind}/{valueToFind}");
        }
        else
        {
            Console.WriteLine($"The hashtable does not contain the key/value pair: {keyToFind}/{valueToFind}");
        }
    }
}