Game Engine for TDD

NebraskCodeGameEngine.cs

using System;
using GameNetworkInterfaces;

namespace TicTacToe.Core
{
    public class GameEngine
    {
        private ICommonGameNetworkControl _network;

        public GameEngine(ICommonGameNetworkControl network)
        {
            _network = network;
        }

        public string GetWinner(string[,] board)
        {
            if(board[0,0] == "X" && board[0, 1] == "X" && board[0,2] == "X")
            {
                return "X";
            }
            return " ";
        }

        public Guid Login(string userName, string password)
        {
            return _network.Login(userName, password);
        }
    }
}