gistfile1.rb

### Usage example

Publisher = Struct.new(:name)
Book = Struct.new(:publisher)
Review = Struct.new(:book)

def Review.publisher
  book.publisher
end

def build_publisher(name)
  Review.new(
             Book.new(
                      Publisher.new(name)
                      ))
end

reviews = [build_publisher('Publisher 1'), build_publisher('Publisher 2')]

p reviews.map(&:publisher) # => ["Publisher 1", "Publisher 2"]