Dynamic wrapper around a JSON serializer (in this case, ServiceStack)

DynamicJson.cs

using ServiceStack.Text;

public class DynamicJson : DynamicObject
{
    private readonly IDictionary<string, object> _hash = new Dictionary<string, object>();

    public static string Serialize(dynamic instance)
    {
        var json = JsonSerializer.SerializeToString(instance);
        return json;
    }

    public static dynamic Deserialize(string json)
    {
        // Support arbitrary nesting by using JsonObject
        var deserialized = JsonSerializer.DeserializeFromString<JsonObject>(json);
        var hash = deserialized.ToDictionary<KeyValuePair<string, string>, string, object>(entry => entry.Key, entry => entry.Value);
        return new Json(hash);
    }

    public DynamicJson(IEnumerable<KeyValuePair<string, object>> hash)
    {
        _hash.Clear();
        foreach (var entry in hash)
        {
            _hash.Add(Underscored(entry.Key), entry.Value);
        }
    }

    public override bool TrySetMember(SetMemberBinder binder, object value)
    {
        var name = Underscored(binder.Name);
        _hash[name] = value;
        return _hash[name] == value;
    }

    public override bool TryGetMember(GetMemberBinder binder, out object result)
    {
        var name = Underscored(binder.Name);
        return YieldMember(name, out result);
    }

    public override string ToString()
    {
        return JsonSerializer.SerializeToString(_hash);
    }

    private bool YieldMember(string name, out object result)
    {
        if (_hash.ContainsKey(name))
        {
            var json = _hash[name].ToString();
            if (json.TrimStart(' ').StartsWith("{"))
            {                
                result = Deserialize(json);
                return true;
            }
            result = json;
            return _hash[name] == result;
        }
        result = null;
        return false;
    }

    internal static string Underscored(IEnumerable<char> pascalCase)
    {
        var sb = new StringBuilder();
        var i = 0;
        foreach (var c in pascalCase)
        {
            if (char.IsUpper(c) && i > 0)
            {
                sb.Append("_");
            }
            sb.Append(c);
            i++;
        }
        return sb.ToString().ToLowerInvariant();
    }
}