Bring Property model from spree core
user
```ruby
module Spree
  class Property < ActiveRecord::Base
    has_and_belongs_to_many :prototypes, join_table: 'spree_properties_prototypes'

    has_many :product_properties, dependent: :destroy
    has_many :products, through: :product_properties

    attr_accessible :name, :presentation

    validates :name, :presentation, presence: true

    scope :sorted, -> { order(:name) }

    def self.find_all_by_prototype(prototype)
      id = prototype
      id = prototype.id if prototype.class == Prototype
      joins("LEFT JOIN properties_prototypes ON property_id = #{self.table_name}.id").
        where(prototype_id: id)
    end
  end
end
```
assistant