public void PeekBackwardWithinBook_OneBlock_WithinBook() { var firstBlock = m_books.First()[0]; var secondBlock = m_books.First()[1]; m_navigator.CurrentBlock = secondBlock; IEnumerable <Block> result = m_navigator.PeekBackwardWithinBook(1); Assert.AreEqual(1, result.Count()); Assert.AreEqual(firstBlock, result.First()); }