private static NetFxToWinRtStreamAdapter AsWindowsRuntimeStreamInternalFactoryHelper(Stream stream) { Debug.Assert(stream != null); Contract.Ensures(Contract.Result <NetFxToWinRtStreamAdapter>() != null); Contract.EndContractBlock(); // Get the adapter for managed stream again (it may have been created concurrently). // If none exists yet, create a new one: NetFxToWinRtStreamAdapter adapter = s_netFxToWinRtAdapterMap.GetValue(stream, (str) => NetFxToWinRtStreamAdapter.Create(str)); Debug.Assert(adapter != null); adapter.SetWonInitializationRace(); return(adapter); }