app/blueprints/variant_blueprint.rb
class VariantBlueprint < Blueprinter::Base
identifier :id
fields :product_id, :parent_product_id, :parent_variant_id
fields :sku, :price, :compare_at_price, :barcode, :selling_policy,
:cost, :open_price
field :default
fields :variant_type, :variant_status, :status
fields :created_at, :updated_at
end