public void ShouldOpenFileAndReadStream()
{
var mockstream = new Mock <Stream>();
mockstream.Setup(x => x.CanRead).Returns(true);
var streamreader = new StreamReader(mockstream.Object);
_csvWriter.Open(Filename);
var stream = _csvWriter.GetWriter();
Assert.That(stream, Is.EqualTo(streamreader));
_csvWriter.Close();
}