System.Collections.ListDictionaryInternal.Contains C# (CSharp) Method

        public bool Contains(Object key) {
            if (key == null) {
                throw new ArgumentNullException("key", Environment.GetResourceString("ArgumentNull_Key"));
            }
            for (DictionaryNode node = head; node != null; node = node.next) {
                if (node.key.Equals(key)) {
                    return true;
                }
            }
            return false;
        }