book.rb

class Book
  attr_accessor :title, :author
  def initialize(args)
    args = defaults.merge(args)
    @title = args[:title]
    ...
  end
	
  def store_book
    # logic for storing the book at a location on the shelf 
  end
  ....
  def defaults
    {title: "Unknown", author: "Unknown"}
  end
	
end