public void CommentLinesUsingSelectLines()
        {
            // Pre-conditions
            Assert.AreEqual(textCore.GetLine(2), "\t\tcruel\n");
            Assert.AreEqual(textCore.GetLine(3), "\tworld");

            textCore.SelectLines(2, 1);
            textCore.CommentLines(true);

            // Post-conditions
            Assert.AreEqual(textCore.GetLine(2), "\t\t//cruel\n");
            Assert.AreEqual(textCore.GetLine(3), "\t//world");
        }