public void CacheTest(string context)
        {
            using (var dc = new DataConnection(context))
            {
                dc.Execute("CREATE TABLE #t1(v1 int not null)");
                dc.Execute("INSERT INTO #t1(v1) values (1)");
                var v1 = dc.Query <object>("SELECT v1 FROM #t1").ToList();
                dc.Execute("ALTER TABLE #t1 ALTER COLUMN v1 INT NULL");

                DataConnection.ClearObjectReaderCache();

                dc.Execute("INSERT INTO #t1(v1) VALUES (null)");
                var v2 = dc.Query <object>("SELECT v1 FROM #t1").ToList();
            }
        }