This is Dynamic custom model t which useful to create object graph where you want your object to be very flexible such as in razor template use cases

DynamicModel

public class DynamicModel : DynamicObject
    {
        private readonly bool _isStrictGet;
        public IDictionary<string, object> _dict;

        public DynamicModel(string objectName = null, IDictionary<string, object> dict = null, bool isStrictGet = false)
        {
            ObjectName = objectName;
            _dict = dict ?? new Dictionary<string, object>();
            _isStrictGet = isStrictGet;
        }

        #region <<Override method>>

        public override bool TryGetMember(GetMemberBinder binder, out object result)
        {
            if (_dict.ContainsKey(binder.Name))
            {
                result = _dict[binder.Name];
                return true;
            }
            //if it can't find any keys
            if (_isStrictGet)
            {
                //if you need to be 
                result = null;
                return false;
            }
            //to make this to return gracefully you can set this to true so that it will return empty string.
            result = new DynamicModel("");
            return true;
        }

        public override bool TrySetMember(SetMemberBinder binder, object value)
        {
            Add(binder.Name, value);
            return true;
        }

        public override IEnumerable<string> GetDynamicMemberNames()
        {
            return _dict.Keys;
        }

        public override string ToString()
        {
            return ObjectName ?? base.ToString();
        }

        #endregion

        #region <<helper method>>

        public void Add(string key, object value)
        {
            if (_dict.ContainsKey(key))
            {
                _dict[key] = value;
            }
            else
            {
                _dict.Add(key, value);
            }
        }

        public bool ContainsKey(string key)
        {
            return _dict.ContainsKey(key);
        }

        public object GetValue(string key)
        {
            return _dict.ContainsKey(key) ? _dict[key] : null;
        }

        #endregion

        public string ObjectName { get; set; }
    }