public void PartialSelectionInvalidForward()
        {
            // Pre-conditions...
            Assert.AreEqual(0, textCore.SelectionStart.X);
            Assert.AreEqual(0, textCore.SelectionStart.Y);
            Assert.AreEqual(0, textCore.SelectionEnd.X);
            Assert.AreEqual(0, textCore.SelectionEnd.Y);

            int startColumn = -100;
            int startLine   = -100;
            int endColumn   = 1000;
            int endLine     = 1000;

            textCore.SelectPartial(startColumn, startLine, endColumn, endLine);

            // Post-conditions...
            Assert.AreEqual(0, textCore.SelectionStart.X);
            Assert.AreEqual(0, textCore.SelectionStart.Y);
            Assert.AreEqual(6, textCore.SelectionEnd.X);
            Assert.AreEqual(3, textCore.SelectionEnd.Y);
            Assert.AreEqual(6, textCore.CursorPosition.X);
            Assert.AreEqual(3, textCore.CursorPosition.Y);
        }