INTERFACE {{p}}if_shipping_cost PUBLIC.
  TYPES ty_weight TYPE p LENGTH 13 DECIMALS 3.
  TYPES ty_amount TYPE p LENGTH 15 DECIMALS 2.

  CONSTANTS:
    BEGIN OF c_rate,
      min_charge      TYPE ty_amount VALUE '6.00',
      express_percent TYPE i         VALUE 35,
      bulk_weight     TYPE ty_weight VALUE '31.500',
      bulk_step       TYPE ty_amount VALUE '0.65',
    END OF c_rate.

  METHODS calculate
    IMPORTING iv_weight      TYPE ty_weight
              iv_express     TYPE abap_bool
    RETURNING VALUE(rv_cost) TYPE ty_amount.
ENDINTERFACE.