public void Increase(Pair searchedPair)
        {
            Pair pair = Get(searchedPair);

            if (pair.IsInt)
            {
                pair.Value = (pair.Int + 1).ToString();
            }
        }
 public Pair Get(Pair searchedPair)
 {
     foreach (Pair element in Items)
     {
         if (element.Key == searchedPair.Key)
         {
             return element;
         }
     }
     return new Pair(searchedPair.Key);
 }