void RoundtripSelectedLines(string testFileName, bool singleLineOnly)
        {
            bool success = controller.LoadInitialFile(TestUtil.GetTestFile(testFileName), true);

            Assert.IsTrue(success);

            // Make sure every line in every tab can be selected.
            for (int tab = 0; tab < selectionMgr.TabCount; ++tab)
            {
                selectionMgr.ActiveTab = tab;
                for (int line = -1; line < selectionMgr.ActiveDescription.Length; ++line)
                {
                    selectionMgr.SelectDescriptionLine(line);
                    Assert.AreEqual(tab, selectionMgr.ActiveTab);
                    int firstLine, lastLine;
                    selectionMgr.GetSelectedLines(out firstLine, out lastLine);
                    if (singleLineOnly)
                    {
                        Assert.AreEqual(line, firstLine);
                        Assert.AreEqual(line, lastLine);
                    }
                    else
                    {
                        Assert.IsTrue(line >= firstLine);
                        Assert.IsTrue(line <= lastLine);
                    }
                }
            }
        }