public void Add(TKey key, TValue value)
{
if (_list == null)
{
_list = new List.LinkedList <IHashTableNodePair <TKey, TValue> >();
}
else
{
foreach (var pair in _list)
{
if (pair.Key.Equals(key))
{
throw new ArgumentException("Already contain key");
}
}
}
_list.AddFirst(new HashTableNodePair <TKey, TValue>(key, value));
}