/home/paul/dev/SqlClient/dev/paul/app-context-switch-test-helper/src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParserStateObject.cs(3441): error TESTERROR:
      Microsoft.Data.SqlClient.ManualTesting.Tests.DataReaderTest.CanReadXmlData (354ms): Error Message: Microsoft.VisualSt
      udio.TestPlatform.TestHost.DebugAssertException : Method Debug.Fail failed with 'snapshot._storage == null
      ', and was translated to Microsoft.VisualStudio.TestPlatform.TestHost.DebugAssertException to avoid terminating the p
      rocess hosting the test.

            if (_snapshot != null)
            {
                StateSnapshot snapshot = _snapshot;
                _snapshot = null;
                Debug.Assert(snapshot._storage == null);
                snapshot.Clear();
                Interlocked.CompareExchange(ref _cachedSnapshot, snapshot, null);
            }