t() :: %EasyPost.Shipment.Rate{carrier: String.t, carrier_account_id: String.t, created_at: DateTime.t, currency: nil | String.t, delivery_date: DateTime.t, delivery_date_guaranteed: boolean, delivery_days: non_neg_integer, id: nil | String.t, list_currency: String.t, list_rate: String.t, mode: EasyPost.mode, rate: String.t, retail_currency: String.t, retail_rate: String.t, service: String.t, shipment_id: String.t, updated_at: DateTime.t}