public void TrimColumns_Test()
    {
        var stream       = WriteStringToStream(Columns);
        var streamReader = new StreamReader(stream);
        var trimmer      = new CsvFileColumnTrimmer();

        trimmer.TrimmColumns(ref streamReader);
        var res = streamReader.ReadLine();

        Assert.AreEqual("col1;col2;col3;", res);
    }
    public void TrimColumns_WithUsing_Test()
    {
        var stream = WriteStringToStream(Columns);

        using (var streamReader = new StreamReader(stream))
        {
            var trimmer = new CsvFileColumnTrimmer();
            using (var reader = trimmer.TrimmColumns(streamReader))
            {
                var res = reader.ReadLine();
                Assert.AreEqual("col1;col2;col3;", res);
            }
        }
    }