docs: public static void showBooks(final ListOfBooks booksList){
     	
      	if(booksList != null && booksList.getBook() != null && !booksList.getBook().isEmpty()){
      		List<BookType> books = booksList.getBook();
      		System.out.println("\nNumber of books: " + books.size());
      		int cnt = 0;
      		for (BookType book : books) {
      			System.out.println("\nBookNum: " + (cnt++ + 1));
      			List<PersonType> authors = book.getAuthor();
      			if(authors != null && !authors.isEmpty()){
      				for (PersonType author : authors) {
      					System.out.println("Author:  " + author.getFirstName() + 
      										" " + author.getLastName());
  					}
      			}
      			System.out.println("Title:   " + book.getTitle());
      			System.out.println("Year:    " + book.getYearPublished());
      			if(book.getISBN()!=null){
      				System.out.println("ISBN:    " + book.getISBN());
      			}
  				
  			}
      	}else{
      		System.out.println("List of books is empty");
      	}
      	System.out.println("");
  	}