public static void TestDisposedAccess() { using var buffer = new ResizableBuffer(); // Write our expected columns to the parquet in-memory file. using var outStream = new BufferOutputStream(buffer); using var fileWriter = new ParquetFileWriter(outStream, new Column[] { new Column <int>("Index") }); fileWriter.Dispose(); var exception = Assert.Throws <NullReferenceException>(() => fileWriter.AppendRowGroup()); Assert.AreEqual("null native handle", exception.Message); }