public void Reattach_Case1(string prefixText, string readerText)
        {
            // Arrange
            var r = new PrependableReader(CharPosition.BeginningOfFile, prefixText.ToArray(), new StringReader(readerText));

            r.Read();

            // Act
            r.Reattach(CharPosition.BeginningOfFile, prefixText.ToArray());
            var p  = r.Position.Index;
            var l  = r.Position.Line;
            var c  = r.Position.Column;
            var ch = r.Peek();

            // Assert
            Assert.That(p, Is.EqualTo(0));
            Assert.That(l, Is.EqualTo(1));
            Assert.That(c, Is.EqualTo(1));
            Assert.That(ch, Is.EqualTo(prefixText.Length == 0 ? readerText[1] : (prefixText + readerText)[0]));
        }
        public void Reattach_Case2(string prefixText, string readerText)
        {
            // Arrange
            var r = new PrependableReader(CharPosition.BeginningOfFile, prefixText.ToArray(), new StringReader(readerText));

            r.Read();
            r.Read();
            r.Read();

            // Act
            r.Reattach(CharPosition.BeginningOfFile.NextColumn, "ab".ToArray());
            var p  = r.Position.Index;
            var l  = r.Position.Line;
            var c  = r.Position.Column;
            var ch = r.Peek();

            // Assert
            Assert.That(p, Is.EqualTo(1));
            Assert.That(l, Is.EqualTo(1));
            Assert.That(c, Is.EqualTo(2));
            Assert.That(ch, Is.EqualTo('a'));
            Assert.That(r.ReadToEnd(), Is.EqualTo("ab3456789"));
        }