Create ValueProvider instead of ILookup

[neuecc]

concept design

        public class ValueProvider
        {
            // object is List[String] or String.
            // optimize way, value is single in many cases.
            Dictionary<string, object> values = new Dictionary<string, object>();

            public ValueProvider(IDictionary<string, object> environment)
            {
                var queryString = "hoge=hage&huga=3";
                foreach (var item in queryString.Split('&'))
                {

                    // values.TryGetValue(
                }
            }

            /// <summary>Returns List[String] or String or Null</summary>
            public object GetValue(string key)
            {
            }
        }