testing something, won't compile

NadekoBot.Core/Modules/Gambling/Services/CurrencyRaffleService.cs

@@ -0,0 +1,45 @@
+using System.Threading.Tasks;
+using NadekoBot.Core.Services;
+using System.Collections.Concurrent;
+using NadekoBot.Core.Modules.Gambling.Common;
+using System.Threading;
+
+namespace NadekoBot.Core.Modules.Gambling.Services
+{
+    public class CurrencyRaffleService : INService
+    {
+        private readonly SemaphoreSlim _locker = new SemaphoreSlim(1, 1);
+        private readonly DbService _db;
+
+        public ConcurrentDictionary<ulong, CurrencyRaffleGame> Games { get; }
+
+        public CurrencyRaffleService(DbService db)
+        {
+            _db = db;
+        }
+
+        public async Task JoinOrCreateGame(ulong channelId, string username,
+            ulong userId)
+        {
+            await _locker.WaitAsync().ConfigureAwait(false);
+            try
+            {
+                using (var uow = _db.UnitOfWork)
+                {
+                    //remove money
+                    if (!await _cs.RemoveAsync(userId, "Currency Raffle Join", _amount).ConfigureAwait(false))
+                        return false;
+                }
+
+                //add to to list
+                if (_users.Add((username, userId)))
+                    return false;
+                return true;
+            }
+            finally
+            {
+                _locker.Release();
+            }
+        }
+    }
+}