// Constructor
public Chapter(Book book, Int32 chapId, Int32 chapNum, ChapterPreface preface)
{
if(book == null)
throw new ArgumentNullException("book");
_book = book;
_chapId = chapId;
_chapNum = chapNum;
_verses = new VerseCollection();
_preface = preface;
if(_preface != null)
_preface.SetChapter(this);
}
