@type t() :: %Merchant.LineItem{
  description: (String.t() | nil) | nil,
  discounts: ([Merchant.Discount.t()] | nil) | nil,
  external_id: (String.t() | nil) | nil,
  image_urls: ([String.t()] | nil) | nil,
  name: String.t() | nil,
  quantity: Merchant.Quantity.t() | nil,
  taxes: ([Merchant.Tax.t()] | nil) | nil,
  total_amount: integer() | nil,
  type: String.t() | nil,
  unit_price_amount: integer() | nil,
  url: (String.t() | nil) | nil
}