public void RemoveFirstEmptyList()
        {
            OrderPreservingDictionary <object, int> dictEmpty = new OrderPreservingDictionary <object, int>();

            dictEmpty.RemoveFirst();
            var keyList = dictEmpty.GetKeys();

            CollectionAssert.AreEqual(new List <object> {
            }, keyList);
        }
 public void RemoveFirstTest()
 {
     dict.RemoveFirst();
     Assert.AreEqual(false, dict.ContainsKey(key1));
 }