INTERFACE {{p}}if_freight_calc PUBLIC.
  TYPES:
    ty_zone   TYPE c LENGTH 2,
    ty_weight TYPE p LENGTH 9 DECIMALS 3,
    ty_amount TYPE p LENGTH 7 DECIMALS 2.

  METHODS calculate
    IMPORTING iv_zone        TYPE ty_zone
              iv_weight      TYPE ty_weight
    RETURNING VALUE(rv_cost) TYPE ty_amount.
ENDINTERFACE.