public void ShouldWriteToTextWriter()
{
var textWriter = new Mock <TextWriter>();
_csvWriter.SetWriter(textWriter.Object);
_csvWriter.Open(Filename);
_csvWriter.Write(new String[] { "newColumn1", "newColumn2" });
textWriter.Verify(x => x.WriteLine("newColumn1\tnewColumn2"));
_csvWriter.Close();
}