Any idea why this isnt working?

module Inventoryable


    module ClassMethods

    def create(attributes)
    object = new(attributes)
    @instances.push(object)
    return object
    end

    def instances
    @instances ||= []
    end


    end #ClassMethods



    def stock_count
    @stockcount ||= 0
    end

    def stock_count=(number)
    @stockcount = number
    end

    def in_stock?
    stock_count > 0
    end
end #Inventoryable


class Shirt
    extend Inventoryable::ClassMethods
    include Inventoryable

    attr_accessor :attributes

    def initialize(attributes)
    @attributes = attributes
    end

end #Shirt


class Trousers

    attr_accessor :attributes

    def initialize(attributes)
    @attributes = attributes
    end

end # Trousers

class Accessory

    attr_accessor :attributes

    def initialize(attributes)
    @attributes = attributes
    end

end #Accessory

shirt1 = Shirt.create(name: "mtf", size: "L")

shirt1.stock_count=(10)

puts "Shirt 1 stock count: %s" % shirt1.stock_count

puts "Shirt 1 is currently in stock: %s " % shirt1.in_stock?